Tearing in VR since 570.x

Since Linux driver 570 (no matter if .86 or .124) I got tearing in VR with the Valve Index on my nVidia 2080 via Display Port. I’m on Ubuntu 24.04 LTS. It’s independent of if GSP is enabled or not or NVreg_RegistryDwords=RMIntrLockingMode=1 is present or not.
I tried both setting it as a grub boot parameter “nvidia.NVreg_EnableGpuFirmware=1 nvidia.NVreg_RegistryDwords=RMIntrLockingMode=1” and sudo update-grub or via module setting in /usr/lib/modprobe.d/nvidia.conf and afterwards using sudo update-initramfs -u -k all (but not grub and modprobe at the same time).

Shaking my head in VR reveals a horizontal line where the upper and lower images have different latency. Comparabel to the latancy introduced here: Latency in VR (with GSync) since 440.44

Where this seperation line occurs seems random, once I was in the upper quarter another time in the lower quarter.

It’s independent of if I use SteamVR or Monado, if async reprojection is enabled or not.

Downgrading to driver 565 resolves this issue, just the rendering latency issue (linked above) remains, just no tearing.

I do not have this issue on my PC with 3070 using HTC Vive via HDMI on driver 570.x (disabled GSP though, as the stutter/lags in VR issue is not solved with setting NVreg_RegistryDwords=RMIntrLockingMode=1)

Looks like the tearing could be OpenVR only. It occurs in Beat Saber 1.29 but not in Pistol Whip, while Beat Saber 1.29 (using legacy beta branch) is not yet OpenXR, Pistol Whip is OpenXR. Needs more testing to narrow it down.

edit: it also happens in Pistol Whip.
Yet as written in the other thread (Latency in VR (with GSync) since 440.44 - #8 by Corben78), the headtrack delay seems gone in Monado with the U_PACING_COMP_PRESENT_TO_DISPLAY_OFFSET_MS=10setting.