an important clarification is that all visual novels stopped running in the same way, but there was nothing about steam_api in the logs anymore, and I couldn't solve the problem with them either...
Viewing post in Shelter (Furry Visual Novel) comments
From quick googling I see steam_api.dll is used for running pirated Steam games (bypassing the connection with the client or something) so that seems unrelated. Shelter isn't even on Steam. Either way, this seems like a problem very specific to your device and it's unlikely anyone will be able to help you here. If you need more help, you're welcome to join the discord server.
I found out what the problem was, and I found a funny solution in the ahaha steam community... The problem really turned out to be very rare in that it occurred to a small number of people, the solution turned out to be as simple as possible: Language and Time settings(Windows 11)/Language Settings(Windows 10) --> Administrative language Settings --> Advanced --> Language of programs that do not support Unicode --> Change the system language --> check the box "Beta version: Use Unicode (UTF-8) to support the language worldwide. After these actions, all the novels began to work as they should.