Mouse problems with display port 1.2 in MST (4K display)

Hi,

I have almost exact the same setup here: Macbook Pro 15", Late 2013 with Dell UP3214Q with the same issue after updating to Sierra. This Mouse-Curser problem drives me nuts. At the moment I can not work properly (graphic designer) because I need several clicks to hit something. Its like the curser on the right side is cached and can be all kinds of curser you want (scale, type ..). As soon as you move the the left side the curser goes over to the normal arrow. And if you move back to the right side its again wrong. I even reinstalled the system (clean install) with all the software (took me a whole day) but the problem still persists. I need a solution for this issue ASAP.

I will try to make some videos to show the problem.

Videos:

Desktop: https://vid.me/WZYK

Illustrator: https://vid.me/Lq45

I can confirm that at 30Hz (DP1.0) the problem disappears but its not a really solution for me. I don't buy an expensive display to work at 30hz.

Same problem here, the only things that fixes it for me is to shake the mouse cursor. Very annoying, bug. I hope they can fix it soon.

Has anyone reported this bug to apple, beside the forums? Do they formally know about it?

Thanks for posting this. I hadn't realized the details of the DP 1.2 vs 1.1 issue.

If anyone at Apple is listening, none of my Windows machines exhibit this issue, and my purchase of a new $3300 MacBook Pro rests entirely on Apple resolving this.

Same here folks, hugely annoying when you're a photographer trying to edit pictures! I changed the resolution on the Dell and that worked.

Apple specifically claims this monitor is supported: Using 4K displays and Ultra HD TVs with your Mac - Apple Support

Same problem here using my DELL UP2414Q on my mid 2014 MBP. I am just tossing my complaint out there to ensure that Apple recognizes the fact that DP1.2 with MST is broken and they need to have a look at it. Took them far too long to (partially) solve the kernel panics that existed in both Yosemite and El Capitan over this protocol, now this... *sigh*.

I'm having the same issue. It's was driving me crazy until I found this post and set the monitor down to DP 1.1, but now the refresh is down so all input is laggy. PLEASE FIX THIS APPLE!

Computer - MacBook Pro Retina 15, Late 2013

Monitor - Asus PQ321

Thanks,

Jim

Same issue with my DELL UP2414Q. Interesting, it only occurs when I use it as a single display with the MacBook Pro lid closed. As soon as I use it as a 2nd display, the problem goes away.

Luke,

Can you repeat this several times across a reboot or two? I find this very odd as I use it as a second display and have always had this issue since Sierra came out. If so, this finding might be useful to Apple (or some of us) as we try to either fix it (Apple, get on this already!) or sort out a work around. Thanks in advance for double and triple-checking this. I'm going to be trying using my MBP in "Clamshell mode", i.e. with the lid closed to see if the issue can be dispatched that way.

Cheers!
Matt

I'm using both monitors now, and at first I thought it was fixed, but after a while the same problem presents itself. The problems aren't as severe as running with one display, but it still exists.