Stutter/lag spikes with DLSS after updating yesterday with kernel/nvidia-open update, anyone else?

After the latest update yesterday, GTA V Enhanced and Dying Light: The Beast started getting periodic huge lag spikes while using DLSS. GPU load drops from ~99% to under 40% and snaps back every few seconds. GPU stays at P0/full clocks the whole time, so it's not a power-state issue.

Non-DLSS games (Subnautica: Below Zero for example) run perfectly fine on the same system.

System: RTX 4070 Ti, CachyOS, Niri, linux-cachyos-nvidia-open bumped to driver 615.71.09 alongside kernel 7.2.5-1-cachyos yesterday.

Reproduced across Proton-CachyOS slr and native, and Proton-GE doesn't matter which. Proton Experimental is unaffected works great with DLSS on.

Switching DLSS off or changing it from Quality to DLAA also fixes it, less fps ofc but no huge lag spikes (PROTON_ENABLE_NVAPI=0 gave inconsistent results across builds).

Oddly, Metro Exodus Enhanced Edition runs fine with DLSS Quality on the same driver, same nvngx_dlss.dll version even, so still really don't under stand what's going on.

Anyone experiencing similar problems? Any ideas why?