Same issue here. For me it happens when I have an external monitor plugged in, which then seems to trigger GPU switch to using the Radeon Pro 560X 4 GB. The UI lag is very noticeable during video calls (Skype, Zoom, VooV). The UI refresh rate slows to a crawl. No crashes in my case, but the computer is barely usable. If I unplug the external monitor I can do the video call just using the MacBook Pro screen with no problems, so this has been my workaround so far.
Infix
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