macOS 10.15.5 broke mouse pointer location on vertical display

I found another workaround:

After re-connecting the cables, I changed the display "Rotation" setting in Sys. Prefs from 90º to 270º (and physically rotated the monitor 180º to match the display's visual rotation) and this has eliminated the mouse "worm hole" issue.

It would be great if this issue could be fixed though.

Merry Christmas.

I have good new for you and all of peoples who have trouble with this annoying bug.

I have founded a way to fix this bug. It 's very simple to do so just follow my guide and

I guarantee It will 100% (tested on other mac too)

1. Login in your mac with only main monitor turning on, keep 2nd monitor turn off
2. In "System Preference" -> "Mission Control" -> "Hot corners" -> Set "Put Display to Sleep" to any available slot
3. Put your main display to sleep by using method in step 2
4. Turn on your 2nd monitor and you are done. Just it.

Example setting, and result video here:

https://youtu.be/LJlIXCndNvM

Sadly, This is just temporary fix and you have to repeat it every times.

1: Make sure you turned off 2nd monitor

2: Put your main screen to sleep mode

3: Wake up your main screen and turn on 2nd monitor

-> all of these process only take < 5s but we still have to wait Apple Dev to completely fix this bug.

Hey there rynop2000,

Thanks for reaching out to Apple Support Communities. I understand the mouse cursor gets shifted when your display is rotated to the vertical position. I’ll be happy to help with this.

Have you reset the SMC and NVRAM on your Mac yet? If not, see if this has any impact on the issue you’re experiencing:

How to reset the SMC of your Mac

Reset NVRAM or PRAM on your Mac

You may also want to test this in safe mode or a new user account and see if the issue continues there if the above steps don’t help:

How to use safe mode on your Mac

How to test an issue in another user account on your Mac

If these don't help, provide details if you're using a wired or Bluetooth mouse.

Take care.

I've been running into this issue as well and ended up just not rotating my screens. After the Big Sur upgrade I thought to try out whether this bug still existed and upon first try it seemed solved! However, after I told everybody that the frustrating bug seemed to be fixed, and after I've gotten a little lunch, suddenly the bug re-appeared :(.

Today I tried using a different cable, and long and behold: The bug was fixed! However, again, after locking my screen and coming back from lunch it re-appeared.

Rotation: 90 degree (screen won't go the other direction)

Screen: LG 27UK850-W

Connectors used: USB-C and HDMI (HDMI -> USB-C cable)

Resolution: Looks like 2560x1440

One workaround that works for me is to option-click on the "Scaled" radio button in the Displays settings, and checking "Show low resolution modes" and then picking "1440x2560 (low resolution)" from the list. This does however mean that I can't enjoy retina crispness, however, it seems to be the least impactful workaround I've found so far.

I'm still intrigued by the idea that this bug appears after a while, seems like I should be able to reset something to get it to disappear again. (I've tried all the SMB resets and such to no avail).

Sorry for my bad english first, I'm not native English speaker.

And sorry again for my unclear instructions.

I mean iMac or MBP monitor itself as "main" monitor, so in your case.

1. First, turn off both 2 external monitors
2. Using your MBP or iMac monitor and set "put display to sleep" shortcut as I my previous guide
3. Put your MBP or iMac monitor to "sleep mode"
4. Wait 1s then wake up your monitor
5. Turn on both your 2 external monitors and check the result

I'm already checked with my 2020 model 16inch MBP and iMac 27 inch + dell u3219q (Rotation: Standard) and u2720q (Rotation: 270 degree) and both working fine. And I have to do this 1 time per day only (take less than 5s) after I wake up my MBP or iMac

So please confirm this newer instruction working or not in your setup env and tell me the result :D

Hey rynop2000,

Thanks for going through those steps. Were you able to test in a new user account as well? If not, try there as well to see if this is system wide or just happening with your account. 

Also, see if changing the display resolution has any impact on this. You can find this under “Adjust video settings” here:

Get help with video issues on external displays connected to your Mac

I hope this helps.

Regards.

Confirmed your solution can temporary fix this bug. Today, I tested with some MBP and iMac and find 1 thing maybe helpful:

1: MBP 15-inch 2019 model --> no issue at all

2: MBP 16-inch and Latest iMac 27 inch --> Bug

3: MBP 15-inch 2019 model + eGPU with Vega 64 card or RX 850 card --> no issue at all

4: Same MBP as 3 but eGPU card change to RX 5700 XT (Saphire Pulse) or RX 5700 (ROG-STRIX) --> Bug

=> so I think this bug only present when MBP or iMac using AMD Navi card (or eGPU with Navi card). Other graphic card seem have no problem at all.

Yep, When you change rotation to 90, this annoying issue appear horizontally (right side)

but, rotation changed to 270 it will appear Vertically (bottom)

That why I'm changed my monitor rotation to 270 to minimum the effect of this ...ing bug

This is how billion company fix small bug :D lol

Using an iPad as a Sidecar display magically solves this cursor problem for me very reliably.

It's crazy, but it works. (While we're all waiting for Apple to fix this.)

Hey rynop2000,

Thanks for testing in a new user and providing that info. If the issue is still occurring after doing all those steps, you may want to reach out to Apple Support at the following link so they can look further into this with you:

Get Support

All the best.

I have noticed this issue and been suffering from this for a while. And I have found that this is a known issue such as https://discussions.apple.com/thread/251702485. However, apple hasn't fixed it yet. Very disappointing. I am not even sure if this will be fixed in the next big sur release.