You can supposedly fix this by setting environmental variables in Heroic. Go to the game in heroic>advanced>environmental variables (wiki page)
Then do the following variable:
Key: LANG, Value: en_US.UTF-8
Key: LC_ALL, Value: en_US.UTF-8
Key: LANGUAGE, Value: en_US:en
People with high end systems (5090s etc) are apparent having a lot of performance issues, and are unable to run the game at 60fps/4k without AI upscaling or frame generation.
There’s also a lot of complaints about stuttering, and the game wouldn’t launch at all for a lot of people when it first came out.
I feel like this is virtue signaling more than actually addressing a real problem with Clair Obscur.