Sorry, that was not the kernel. It was (is?) a bad usb socket. I plugged the monitor to a different usb-c port and it works without complaints on all tried kernels (5.6, 5.8, 5.9).
Device: "20NYS8QG0B (LENOVO_MT_20NY_BU_Think_FM_ThinkPad T490s)" -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1856608 Title: [Regression] usb usb2-port2: Cannot enable. Maybe the USB cable is bad? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1856608/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
