Games do not run with Proton 7.0 or Proton Experimental with hybrid graphics enabled

I have been seeing this issue since the release of Linux kernel 6.0 and Nvidia driver 5.10. If using Proton 7.0 or Proton Experimental (or GE-Proton 7.38 or 7.41) while my laptop is running in hybrid graphics mode, the button shows "Running" for as long as a few minutes, but no loader or splash screen becomes visible.

My system is a Lenovo P15 laptop, with an Nvidia Quadro T-1000 and an Intel CometLake-H G2, running Debian Sid. The issue has persisted across several weeks of software updates.

Normally I start games with launch options:
__NV_PRIME_RENDER_OFFLOAD=1 __VK_LAYER_NV_optimus=NVIDIA_only __GLX_VENDOR_LIBRARY_NAME=nvidia %command%

The games seemed to behave the same way with no launch options, when presumably they'd be defaulting to the Intel video drivers.

I've seen this with all Windows games I've tried, specifically:
Helldivers
No Man's Sky
SpaceEngine
Dishonored
Hardspace: Shipbreaker

Linux-native games, with the same launch options, run without difficulty, specifically:
Hexcells Plus
Baldur's Gate: Enhanced Edition
Caves of Qud
Rimworld
Tabletop Simulator

If I switch to Proton 6.38, the Windows games run fine (setting aside an error message about input devices with No Man's Sky that doesn't seem to affect anything.)

I also found that when in my laptop's BIOS, I switched my display mode from hybrid to discrete, and launched the games without launch options, they ran fine with Proton 7.0.4 or Experimental.

Prior to the kernel and driver update, I ran the same games with Proton Experimental or with Proton 7.0.2, without difficulty.

Attached files:
System information
Proton log from SpaceEngine
Internal log from SpaceEngine, se.log
Internal log from SpaceEngine, launcher.log

se.log, line 27:
[MT] ERROR: seSplashWindow::Create(): Window creation error

I feel like somewhere in the course of troubleshooting this, I've seen "window creation error" before.

Start with the attached system information and Proton, se.log, and launcher.log files, especially the reported window creation error. Compare behavior between Proton 6.3.8 and Proton 7.0 or Experimental in hybrid graphics mode; done means the affected Windows games launch successfully there.