How to stop dock from moving on dual monitor system

OK, I seem to have solved this in High Sierra, at least. Reboot the machine to make sure the dock is where you want it and everything else is closed. Do as is suggested in the above posts. Go to System Preferences, then Mission Control. Untick the box that says Displays have separate Spaces. Close that window. Log out. Reboot. Since doing that, my dock has stayed on the primary monitor, as I want. Also, Apple programs that I want to open on different monitors do that and re-open there the next time. (Previously only third-party programs would reliable open again on the monitor they were closed on.) So, problem solved for me.

To answer the OP.

Don't leave the mouse (cursor) at the bottom of the other screen.

Here's the "gesture" to get the dock back in to the right place.
Put your mouse (cursor) at the bottom of the screen where you want the dock to go.

Sorry that this is a workaround. I found this maddening for a LO~~~~NG time. I didn't know what I was doing to make the dock randomly jump to the other screen. Now I know. The suggestion to put your mouse at the bottom of the target screen will save steps. I use to go to System Preferences and jiggle the target monitor in Monitor Setup until the dock went back to the correct monitor.

Now that I know this, I can go to the second monitor, hold my cursor at the bottom of the screen, and get the dock to pop over. Then I can use it for whatever I want to do. When I want it to go back, I hold the cursor at the bottom of the other screen.

Apple should have put a way to disable this in System Preferences. I guess I can see why people would want to use it. But when it seemingly happens for no reason, it's just annoying.

This is a bug, not a feature. If a user wants the Dock to remain at the bottom of the principal display, it should be able to be locked to that position. Not to have this ability without interfering with other functionality is just simply poor programming. All the above mentioned "solutions" interfere with functionality in one way or another.

There is however a simple workaround that doesn't require rebooting or turning off other features, or fiddling with the mouse pointer: go into System Preferences, select Dock, for the positioning press the LEFT radio button, the press the BOTTOM radio button, and the Dock will revert to where it was in the first place.

HOWEVER one should not need to do this. Enough people are annoyed about this BUG that Apple should just fix it. Can't be rocket science.

They did include a way to turn it off, although it's not obvious.

System Preferences > Mission Control > Uncheck Displays have separate Spaces (requires log out)

Should solve your problem, in the event you're still looking for an answer.

I think the most irritating thing here is this was ADDED at some point-- the dock used to always be on my primary screen (the one I designated to have the menu bar.) The problem is Apple, like it always does, doesn't give their customers choices, it forces them down everyone's throat because they think they know what's best for everyone.

Do you have the menu bar in only one screen or in both?

This setting is governed by a checkbox in System Preferences->Mission Control:

"Displays have separate Spaces"

I have it enabled, which gives a menu bar in both screens.

Perhaps for your own preference you might try disabling it (requires log out and log in for the change to take effect).

I haven't tried, but I think that way the Dock will only stay in the same screen as the menu bar.

Or... you might try getting the Dock really out of the way, by putting it on one side instead of the bottom. When placed on one side, the Dock only shows in the corresponding screen; plus it is much harder to accidentally activate it.

I have this issue as well and hate that Apple didn't fix it in High Sierra.

For the guy in this thread that just doesn't get it, there are many use cases where one wouldn't want the Dock moving around. MacOS automatically resizes windows on the screen it moves the Dock to. I have meticulously arranged my toolbars in CAD to fit on my screen exactly how I want them. The same goes for Photoshop, Illustrator, etc. I have my MacBook (where I want to Dock to stay), and 2 Dell ultra-wide screens, on which I run Windows-based CAD software (via Parallels), Office apps and the Mac version of Creative Cloud. Ideally, I'd be able to lock the Dock to the MacBook screen, using that screen for Messages, ShoreTel, Slack and opening Mac apps, while using the rest of my apps at 1/2 or 3/4 screen sizes on the other monitors, with the Windows Task Bar at the bottom of the center screen. As it is, when working in the timeline in Photoshop, the Dock switches over to that screen and resizes my window(s). When opening the System tray in Parallels/Windows, the Dock moves to that screen (occasionally in the way of what's behind it) and generally wrecking workflow.

None of the options currently offered by MacOS/Apple solve for this situation. I could imagine that video editors and web developers would prefer to have their tools and the Dock reliably locked in place as well. When you say that monitors' aspect ratios allow for better Dock placement on the edges of the screen you neglect the fact that multiple application windows will fit the screen better with the Dock on the bottom.

I've sent suggestions for this to Apple for every version of MacOS since they came up with this "feature" and there's not even a Terminal command to shut it off. It's extremely frustrating that we get things as useless as Mission Control and a Holiday Mobile screen saver, but we can't get real matters of user interface handled.

You want your mac to work in a different way than it works today. Only Apple can do that.

All you or me or anyone can do is submit feedback and make a feature request.

http://www.apple.com/feedback

I've been reading this thread and you haven't been very helpful, Luis. You keep telling people to change their workflow and not providing an actual solution.

I am in the same boat. I don't want to make the dock automatically hide nor do I want to use tabs to quickly switch between applications. I want the dock to be visible on my main screen and not automatically move to my alternate screen.

Here's a use case:

- Have your dock always visible

- Have a terminal window open on another monitor and make sure it's maximized (but not full-screen) so that the bottom of it reaches the bottom of the screen.

- Try to resize its height. The dock will suddenly appear and not let you resize.

Here's a gif of me trying to resize my terminal and the dock getting in the way: https://media.giphy.com/media/26zziKNOHvEkgoIgM/giphy.gif

I've been researching this same issue, and in reading your replies, you offer no solutions, only ways to completely change the workflow. I guess you're not understanding the fact that many of us don't work the way you do. I cannot have the dock on the left side of a monitor due to multiple applications that conflict. I find hiding the dock annoying, as I use several apps that show status information in their dock icons.

My personal guess - based on 28 years as a Mac user - is that this is a bug that Apple just doesn't want to fix. I cannot see how it could be considered a feature.

Luis,

I put my comment in to add to the conversation; that having the dock jump from monitor to monitor also impedes other work being done in other applications. This was new content, and why I added it; sometimes completely framing a problem in will help the people who are responsible for the code figure out a solution.

You, on the other hand, merely reiterated suggestions you had made before IN THIS THREAD. Obviously I would have read the thread before replying-- so you added no new content. I appreciate your suggestions but they aren't helpful.

None of us here are expecting Apple to fix things; the way to do that is to file a Radar.

I have this same problem, for completely opposite reasons. If I have a field at the bottom of the screen and I go to click in it to fill it in, and I overshoot, the dock SPRINGS into being in front of the field I'm trying to type in.

I want the dock on my big monitor and want it to stay there. If I put Messages on my laptop screen every time I try to respond to a co-worker I get the Dock in my face.

I think the most irritating thing here is this was ADDED at some point-- the dock used to always be on my primary screen (the one I designated to have the menu bar.) The problem is Apple, like it always does, doesn't give their customers choices, it forces them down everyone's throat because they think they know what's best for everyone.

Part of the reason I was a fairly early adopter of Mac was because of their willingness to listen to customers. By keeping these kinds of threads active, they also will see that there is an interest - and displeasure with - the "feature."

I have already submitted feedback and received the charming form e-mail reply. I followed this thread to see if there was anything useful, but was sadly disappointed to see nothing more than your multiple Windows-style "it don't work like that" replies. If you don't have anything useful to add beyond "it don't work that way," don't add it.

Luis Sequeira1 - These are hands down, some of the most unhelpful replies to a very clear and straightforward question. If you can't answer the question then just keep quiet.

I'm interested in ways you can actually fix this problem, instead the thread is gummed up with your nonsense replies which have no bearing on the actual question.

SHUT UP.

This is depressing. I'm a brand-new Mac user after 25 years of PCs and I come across an almost two year old thread and still no solutions! The blooming dock hops back and forth between my two screen, and as of yet, I've not managed to successfully talk it into returning to its original screen without rebooting. I'm using a third-party mouse, which may account for why it is not responsive to mouse movements to get it back. Indeed, it doesn't always appear to need a mouse movement to take off to the other screen in the first place. It just goes there. I don't want to change my work habits. I don't want the dock up the side or around the corner or anywhere else. I just want it to stay put where it originally was. Surely someone, somewhere knows how to make this happen.

I've been using a second monitor for my iMac for a long time. I have always kept my dock on the exterior monitor. It has always been there even after my computer sleeps...UNTIL...I upgraded to High Sierra. Since then my dock always switches back to my main screen. I don't want it on my main screen but I don't get the option. I wish there was a setting that allowed me to lock my dock on my exterior monitor. I mean my dock will be on the exterior monitor, my computer goes to sleep for about 2 seconds, I wiggle my mouse or tap the keyboard, and the dock is back to my home screen. This just started with High Sierra.