Lost output to one DP monitor after mainboard BIOS update

I updated the BIOS on my ASUS Pro WS X570-ACE to version 1201 in hopes that it would fix the Xid 61 issues I’ve been having with my EVGA branded RTX 2070. Unexpectedly this broke video output to one of my DisplayPort monitors. I originally had driver version 440.36 installed, but updating to 440.44 didn’t help. When I try to configure the monitors with randr, I get this error:

xrandr: Configure crtc 0 failed
X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 140 (RANDR)
Minor opcode of failed request: 21 (RRSetCrtcConfig)
Value in failed request: 0x0
Serial number of failed request: 53
Current serial number in output stream: 53

The crtc number and request serial numbers change, but otherwise it’s always the same. It’s always the same monitor that doesn’t work, regardless of which DisplayPort connector it’s attached to. However it works on boot until I start Xorg. Initially xrandr shows modes for it, but after swapping cables back and forth a bit it just sees a connected monitor with no modes.

The monitor works in Windows 10 with the same GPU. It also works on my Windows 10 laptop through a USB-C DisplayPort adapter. In Linux I can get an image on it through DVI-D. So I don’t think any hardware is broken in any way.

My Linux distribution is Debian unstable, with kernel 5.2.14 (custom configuration).
nvidia-bug-report.log.gz (942 KB)

Looks like this is related to the Xid errors I’ve been getting rather than the BIOS update. After another Xid error and a warm reboot the other monitor stopped working on DP. I then turned everything off, waited a bit and turned the things on again, and now both monitors are working on DP once more.