I am using a Dell Precision 3570 laptop with Ubuntu 22.04.1 LTS, plus a Dell TB16 Thunderbolt dock to allow easy connection to my desk monitors. The USB, power button, ethernet, and HDMI port on the dock all work fine, but the display port does not seem to be recognised at all. Both screens have HDMI inputs only, so the working connection is HDMI to HDMI, and the connection that isn't working is Display Port to HDMI. Using Windows on the same laptop, both ports work without issue.
I have tried:
- Switching display drivers from X.Org X server to thenvidia-driver-525-open (proprietary, tested). This didn't help, andmeant my laptop would take 3 or 4 attempts to boot properly
- Updating the Linux kernel from 5.15 to 6.19. This changed nothing and I've downgraded back to 5.15
- BIOS update. Initially nothing but the power button was working, updating the BIOS to 1.9.0 fixed everything but the display port.