Default file permissions on upload attachments

HI, I've been using Akaunting on-premise very successfully for some years but have always had an issue with the default file permissions being set incorrectly for any files upload to the system as attachments. I have simply been re-running the default file permissions scripts to fix this but it is becoming a little more than annoying now. If I look at what the permissions *should* be when working correctly, they are drwxrwsr-x but the default file permissions being set by the app are actually drwx--S---

Any ideas on how/where to change these default permissions for uploaded files?