I’ve just connected three new Samsung 28" LU28R55 monitors to my Mac Mini M1 via a UD-ULTC4K.
The directly connected monitor operates at 4K but the other two via the DisplayLink only show 2K.
I am running DisplayLink software v1.5.0 Build 58.125.
Thank you for contacting Plugable support! Sorry to hear about this issue.
We received your direct email with the diagnostics you sent and are taking a look now. You will be getting a reply there shortly with some suggestions on how to resolve this problem.
Thanks again for contacting Plugable support and best wishes!