Hey @EGU973002022 welcome back and thanks for supporting the snap 
can you please be clear what you mean when you say Nextcloud cannot connect to ClamAV?
- since when is suddenly?
- what changes took place since this issue has appeared?
- is ClamAV a service hosted on a separate host?
we’ll definitely need logs to get to the bottom of this. so please run the debugging script or check out How to manage Nextcloud snap logs to find and get those logs.