External Display USB-c Monitor issue

Switching to usb-c to display port cable resolves the issue. But then you would have to use a separate USB cable for the monitor hub. Hopefully Apple will do some due diligence soonish and fix their broken update. Welcome to the Windows world where the users report the bugs.

I have two 31" monitors running Big Sur. One connected using my HDMI port and then I have a USB to HDMI cable running the other. I'm told by Apple Big Sur will not run a dual monitor setup. You seem like you know what you are doing. Any suggestions for a work around?

I’m currently having the same issue. The only solution for me is rebooting my MacBook. It seems that sometimes that solves the problem, but it happens very randomly.

I have a MacBook Pro 16 (2019) and a LG QHD (27QN880)

I have the same problem on a 2019 MacBook Pro 16" connected to a Philips Brilliance 346P1CRH display via USB-C.

Since updating to macOS Big Sur 11.1, the display modes are no longer correctly detected. The display is identified as being 38,5-inch (2560 × 1080), even though it is a 34-inch (3440 × 1440) display. Only resolutions up to 2560 × 1080 can be selected in macOS.

Is is possible to get Apple Tech involved and actually escalate this and solve this issue? I am running 2xc LG 34" and 27" monitors that Cost me 1500$ and they are both displaying very bad text quality, colors are off. I had this issue fixed previously in Catalina, now the "fix" using the ruby code stopped working.

It really is beyond comprehension that so many of us are experiencing this and Apple have said or done nothing since point one was released and did this to our expensive monitors.

Apple are you hearing us???

I believe there's no software solution yet. We need to wait for Big Sur 11.2.

You either get lucky and your screen miraculously works (if it does, don't close your MBP lid or don't put it to sleep), or you wait for the patch.

Apple is aware of the issue and is working on fixing it, but it appears it isn't as simple as we would all like. I've heard 11.2. beta was released in order to test if 'external monitor issue' is resolved, and users still reported the same problem.

Interesting that a new machine doesn’t have the external monitor issues. I suppose I’ll try an exchange with my M1 MacBook Pro as well. I’m at my wits end and will be selling it and getting something else if this isn’t fixed soon.

I spoke to Apple support during the festive break and have provided the information that I was able to gather on this issue. Since then I have reinstalled Catalina, doing a clean sheet install. No monitor issues are present and I am able to work properly.

@Kimochero - I didn't get issues when sleeping and waking up. I think the monitor issues appear when you unplug your monitor cable and then plug it back in. If you don't need to take your laptop away on some errands, just leave it connected to the monitor like a desktop :)

@Nikitav - I was able to trick 11.1 into showing the full capacity of the monitor by rebooting the MacBook in safe mode and then back into normal mode. But I have a 16" pro, no the the M1, so not sure if this will work for you. Hope it does. Since you are using a desktop, you may be more unlikely to take out the monitor cable out. As far as I have seen, if it starts working, until you reboot or take out the monitor cable - it works.

hopefully 11.2 does some justice to an otherwise nice MacOS 11..

I started having this issue with my LG Ultrafine 4k displays. The primary display connected via Thunderbolt has no issues, however, the secondary display connected via HDMI->DisplayPort->USB-C stopped working AFTER updating to 11.2.

I have opened a ticket with Apple Support, and they are escalating the issue to engineering. I will try to report back with their findings.

That is very disappointing news.. Even more so, as I believe, it is a statement that Apple doesn't care. Obviously their M1 line is doing well and they will have many new acquisitions because of it. So the support of their flagship 16" MacBook Pro line is down in the drains as their focus has shifted. This is very, very disappointing for me. Luckily my Macbook is still under warranty, so I will be diligently considering going to the local distributor and throwing it back to Apple to get a refund. I was very much hopeful that 11.2 would fix all problems with external screens.

That's pretty ridiculous if true. I'm currently using a Thunderbolt dock that Apple sells online. It only has USB-C and DisplayPort for monitor inputs. So now I've got to go from HDMI > DVI > USB-C on my dock and hope that it works?? Yikes.

Guess I'll try HDMI > USB-C first and report back.

For context USB-C to USB-C directly from my monitor also doesn't work properly.

Hi @alan7467,

I find that confusing as well. Apple support did also note that USB-C directly is NOT supported either.

I have not been able to find USB-C to DVI cable that takes the input from dvi and outputs to usb-c. Please let me know if you find one that does that.

I have two of those, and they are actually Thunderbolt displays that do also accept USB-C input. However, I don't believe Macs output actual USB-C signals from their Thunderbolt ports, so while the form-factor is compatible, the signaling is not.