You have probably already seen the official notice about this. There is an issue with generations in enhanced compatibility mode right now. They fail and you do not get refunded for the failed generations. I don't know more details at the moment. You just should not use enhanced compatability until this gets fixed. Here is the notice in "known issues": https://civitai.red/issues?id=8
For other questions regarding temporary restrictions in the generator, see this official article: https://civitai.red/articles/30980/a-gpu-crunch-and-bumpy-days-ahead
Update (9th of June 2026 9:00 pm UTC): Enhancend Compatibility has been disabled as of commit d438ad3. I guess it's for preventing users to use a function not working and will probably restored once it's fixed (fingers crossed).