Only since updating to High Sierra from Yosemite, whenever I've had a second monitor attached, the dock keeps randomly moving to it for no reason, and ONLY when I'm not doing anything with the mouse.
MacBook Air, macOS High Sierra (10.13.4), Core i5 Quad, 4GB RAM, Early 2014
if you move your mouse cursor to a screen and leave it in the bottom part of the screen for around 10 sec the dock will move to that screen until you do the same on another screen
elh0ff0_vi wrote:
But it's ONLY when the cursor is on the primary monitor.
IIUC, you are saying that the cursor is on the primary monitor, does not leave this monitor, and the Dock all of a sudden changes from this monitor to the second one. Is that correct? If so, I have to say I have never seen that.
You may want to make sure that in System Preferences->Displays, the "main" display is the one you intend, by ensuring that under "Arrangement" that is the one with the menu bar on it (just drag it if it isn't).
In any case, it should not matter, but it doesn't hurt to try.
In addition to what Rudegar said: especially with a two monitor setup, consider putting the Dock on one side.
This way it never moves, plus as the screen is much wider than it is tall, this save precious vertical real estate.
But it's ONLY when the cursor is on the primary monitor.
Dock keeps moving between monitors randomly
