Detroit: Become Human (1222140)

Compatibility Report

• Name of the game with compatibility issues: Detroit: Become Human
• Steam AppID of the game: 1222140

System Information

• GPU: GTX 1070
• Driver/LLVM version: nvidia 440.82
• Kernel version: 5.7.4
• Link to full system information report as Gist: https://gist.github.com/rkfg/184cc2c1786e18b020b42df850e33aa5
• Proton version: 5.0-9

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

Symptoms

The game works mostly fine and I played 4 hours so far with no crashes or glitches, except it seemingly crashed on the first launch right after installation, no idea why. The compatibility tool wasn't forced in the properties, after I did that it worked.

My issue is frame time spikes (=FPS drops) that are probably caused by CPU load. They're not very annoying but noticeable. They don't present on Windows as can be seen in this video comparison (not mine): https://www.youtube.com/watch?v=iH81xrJLTdM (notice the frame time spikes on the Wine frame time graph)

There's an area in chapter 3 where it's easy to reproduce this slowdown, the CPU usage jumps almost to 100% (all or most of the cores are used) and the game stutters for a bit. It does not look like shader compilation because they're precompiled on first run and this happens in the same area, not on entering some new area. It can be reproduced many times as well. I don't know much about Wine internals but there was an issue with the demo although the FPS was consistently very low, not like it is now.

Reproduction

Here's my video of the said stutter: https://youtu.be/LC2xYzX1Ktc
In this alley when you turn around near the crossroad, FPS drops and CPU usage spikes. After some time it goes back to normal until you walk away and return to this place.

Start by reproducing the chapter 3 alley slowdown with Detroit: Become Human under Proton 5.0-9, using the listed GTX 1070, driver, and kernel details. Compare the behavior with the provided video and collect the requested PROTON_LOG=1 output; done means isolating a reproducible compatibility cause or documenting a verified fix.