Big Sur Issues with Large Monitors - Using a Mac Pro 13-inch, 2020, Four Thunderbolt 3 ports, very buggy with Samsung 49 inch large monitor, sometimes have to reboot to get display to operate correctly, works just fine on Linux or Windows OS
I just upgraded from a Mac Book Pro 17 inch to a Mac Boot Pro 13 inch with 4 Thunderbolt 3 ports, previous Mac Book Big Sur, new Mac Book Big Sur. Display output to my existing Samsung 49 inch monitor extremely buggy since upgrade. Often, a reboot or disconnect/reconnect monitor will resolve the issue. Was flawless on previous Mac Book Pro. Monitor also flawless when attached to either a Fedora 8.x kernel on Intel or a Windows 10 OS on Intel. Sometimes System Properties->Display gets real goofy with this monitor and the only fix is to reboot the OS. I am a developer. I personally doubt the issue is the monitor since it works fine on other platforms as well as a previous Intel silicon MAC Book Pro. Multiple OS updates have not resolved this issue. Connection is via HDMI to a dock, which is connected to the MAC via Thunderbolt 3.
MacBook Pro 15″, macOS 11.3