Big Sur 11.1 External Display Issues!

I have exactly the same issue after the latest update, I have a DELL U3417W and BenQ SW271 attached. The BenQ was not recognised correctly anymore,

After an extensive troubleshooting call with Apple support which didn't solve the case, I had to downgrade to Catalina to solve the problem :-(

Hope they'll fix it soon, I really liked Big Sur (before v11.1)

(MacBook Pro 16" 2019)

Updated on christmas eve and now my BenQ 34" monitor looks like a VGA screen from back in the day. No options I can see to downgrade back to 11.0.1 Not good. And this comes right after seeing Apple announce Apple Car. Could you imagine this type of roll out for something like that? Again, bad news all around :-/ ugh.

Same issue,

MacBook Pro 16" <-- BenQ PD3220U (vía Thunderbold 3) <-- Dell U2715H (Connected to BenQ USB 3 Input)

This setup worked in Catalina. Yesterday I updated to BigSur and I've found this annoying display issue.

I'm also experiencing this or a very similar issue. After the Big Sur update (14.1) external monitors aren't being recognized or resolution downgraded to 1080p. I have 3x Benq PD3220u 4k monitors on a 2019 Macbook Pro that worked without a glitch on Catalina. 2 of the monitors are daisy chained on the left bus, the other is by itself on the right bus. You can tell that the USB bus doesn't feed the daisy chained devices a signal instantly, there's a lag or no signal. This never happened in Catalina where they woke up flawlessly from power nap. I even use the $$$ 2m Apple branded Thunderbolt3 cables.

Reboots don't solve the problem. There's usually a different monitor coming online each boot. I've stopped daisy chaining and now feed 3x cables directly into the MBP. This doesn't solve the problem either and one of the screens comes back as 1080p with the other two at 4k if I'm lucky.

Apple please FIX THIS.

Has anyone found a way to trigger an re-scan of Thunderbolt bus without rebooting the MacBook Pro?

Edit: the BenQ Display Pilot App now also struggles correctly identifying screens 1, 2 and 3 and will highlight the wrong device.

Just wondering if besides postíng here we can take this nasty bug to Apple directly.

Last thing I’d like to do is going to a store and consult one of the geniuses about this issue. I wouldn’t like to go there carrying my 4K screens in a trolley so they can see the issue

This is the first time I have encountered such a serious bug in years of Mac usage - does Apple read these forums? I assume everyone who has posted on here has also sent a bug notification to Apple - the more of us who do this the better.

I spoke to tech support a few days ago and worryingly they claimed that my call was the first they had heard of this issue, and they weren't aware of other users having problems. Like others I am very frustrated that my expensive monitor is currently of little use. Luckily I am not working much over the holiday period, but when I 'return' in January, this is really going to dent productivity.

I'm having the issues as well and I've been talking with senior techs for the past few days. Sounds like the issue is on their radar but I'm sure it wouldn't hurt for everyone else to also call in as well.

2019 16" MacBook Pro

32" BenQ PD3220U

I have exactly the same problem. I manage to turn on the correct resolution, but the monitor is stuttering very badly (probably 20-30fps). Apple, please fix it! It is impossible to work normally on a 4k monitor.

Monitor model: LG 32UD99-W

Same here. Seems this is all over the internet as an 11.1 issue. They screw up every single upgrade. It's the only thing Apple do reliably these days.

I guess the days of folks being proud to work there are long passed.

I've found that most of the time I can get back my Samsung Odyssey G9's native resolution by unplugging and replugging the display if, when the laptop (16" MBP) wakes it's reverted the resolution.

Today, that wasn't enough and I also had to open displays preference and re-select "more space" or option-click scaled and select 5120x1440.

I am getting 60hz refresh according to my monitor. Though it is capable of 240hz, I don't think the MBP is up to that.

Is this the same problem? My external monitor is Sceptre. Computer is MacOS Big Sur version 11.0.1. The display on the external Sceptre is stretched. We’ve tried all the display resolutions and it’s still stretched. MacOS Catalina worked fine on this external monitor. The guy at Apple said I need to get a compatible monitor and sent me a link for a $5000 monitor. What?

Is this the same problem? My external monitor is Sceptre. Computer is MacOS Big Sur version 11.0.1. The display on the external Sceptre is stretched. We’ve tried all the display resolutions and it’s still stretched. MacOS Catalina worked fine on this external monitor. The guy at Apple said I need to get a compatible monitor and sent me a link for a $5000 monitor. What?

I have a 2019 MacBook Pro which I use with a Samsung 49" RG90 external monitor. While it was annoying to find out my graphics card was unable to obtain the 5120 x 1440 monitor resolution capability, I was able to obtain 4096 x 1152; now that I updated from Catalina to Big Sur (11.1), I can only obtain resolution of 1920 x 1080, plus my refresh rate dropped from 120 to 60. Apple support is no help and acts like they don't know it is an endemic issue. No joy to have a $1,000 monitor running at 1920 x 1080. I really hope Apple gets this figured out ASAP.

Same problem with my external ViewSonic VX3276 4k MHD monitor. Upgraded to 11.1 on my Macbook Pro 2019 with my AMD Radeon Pro 5500M graphic driver and I cannot get 3840 resolution anymore. Tried various workarounds to no avail.

I was kindly contacted by an apple support represenative today who called to ask for dianostic infromation they could send to the os engineers to help diganose the issue.

Seems apple do seem to be genuinely taking the issue seriuously. I've supplied a large system diagnostics dump so hopefully this will be sovlved in the not too distant future.

Good luck all!