External camera laggy - low frame rate

Having the exact same issue. With my old 2016 MBP 13-inch, Two Thunderbolt ports, the Ultrafine 5k's camera works flawlessly. With the new 2020 MBP, Four Thunderbolt ports, the camera is nearly unusable most of the time, with one frame per ~5 seconds.

I have had other issues like magicmarc describes — the monitor will occasionally go black for a second or two, and audio is not entirely reliable (mine doesn't "break up," it just stops working altogether until I change audio output settings, or sometimes unplug and reattach the monitor). However, I had these issues with my previous laptop (2018 MacBook Air) as well and they've been present since I purchased the monitor (secondhand) several years ago.

The issue with the camera, however, is new and directly related to my new MacBook Pro.

I haven't noticed any other issues aside from the camera problem. Speakers seem fine, video signal seems fine.

That's great that Apple is looking into this! Although, I really hope I don't have to send my Mac in; it's my new work machine and I've just gotten my dev environment set up the way I like it. Plus, it'd be a huge hassle to be without my work machine for a few weeks. I'd have to consider that.

I removed my stand to check my model number, and it's 27MD5KA

I have the same issue. I just set up my brand new 2013 Macbook pro and connected it to the LG 5K monitor. The camera is so laggy it is unusable. It was just fine yesterday, using my 2019 macbook air. Now suddenly the LG camera is extremely laggy. I will also note that selecting one of my two other cameras works fine (the built in FaceTime camera and a USB connected Logitech Brio). Go figure!

I'm having exactly the same issue as everyone else is reporting.

MBP 2020 2.3Ghz + LG 27MD5KA = Laggy video from LG camera, but perfect video from the MacBook camera.

The LG camera works fine when connected to my Air or Mini.

Have done all of the things OP suggests.

Apple support said there is a software update coming. Let's hope that's soon.

It was over support chat (so take with a grain of salt), but the guy effectively said "yes, pretty sure there's a software update coming". No time frame unfortunately.

I feel like this has got to be affecting a lot of people. That said, I Google'd for AGES to find this thread (I'm like - surely someone else is having this issue!!!).

Very interesting. I wonder if this is a fully pervasive issue in all cases. Has anyone seen or heard evidence of anyone *NOT* seeing this issue? I.e. using a 2020 13-inch MBP with the LG 5k and the LG’s camera works flawlessly? If this is presenting in all cases, I’d guess it’s affecting more people than we’re seeing here. However, it could also be more intermittent and not affecting everyone in this way.

Same issue upgrading from 2019 to 2020 MacBook Pro 13". Talked to Apple here in Norway and they don't even want to look at this thread and require me to reinstall my mac before they escalate the issue.

I have the exact same issue. The LG camera works fine on my 2016 macbook pro but completely unusable in the new 2020 macbook pro. No apps that use the camera that I tried work - quicktime, zoom, photo booth, skype.

I even had the opportunity to test it before I upgraded to 10.15.5 and after. Same issue. However, my 2016 works just fine with 10.15.5.

I think I am still in my return period and I just might return it...it is completely unusable and I don't want to change around my setup that I use 75% of my day (on zoom calls).

Further question: In addition to the super low camera framerate and the occasional audio problems on the Ultrafine 5K with the MBP 2020, does somebody also have occasional complete system crashes (screen freezing for ~10 seconds, then restart)? I have had them a few times now, and each time was (maybe coincidentally?) while connected to the Ultrafine 5K.

Glad I found this thread as I'm having the same issue. Just upgraded to a 2020 13 MacBook from a 2018 15 MacBook.

Was working fine before the switch. Now the lag makes it unusable. I will report as well.

Same issues. LG UtraFine 5K monitor display camera lagging and low frame rate when connected to new MBP 2020, four Thunderbolt 3 ports. Issue in any app using external display camera. Display camera worked fine with late 2016 MBP. I have swapped out connecting between the two MBPs and without fail the 2020 has issues.

On similar note, I too have had issues with display flickering or not connecting or problems with volume tight my 2016 MBP. Those issues have been reported often. Very intermittent so hard to troubleshoot. But I lived with it. The new problem with the display camera is very frustrating given the increased use of camera during remote work and teaching.

Sent bug report.

I talked to Apple support and tried creating a test admin account, reinstalling os, trying it in safe mode, reset SMC, reset NVRAM. None of that worked. Then I was escalated to Senior Support person. We talked through everything in detail and sent all my logs and a video of the problem to their team. They said I should hear back something on Monday. Either they're already aware and working on it, or maybe now there's enough info to investigate.