My issues are different. I'm running Sonoma. I can load and save fine, but since updating to Logic 11.2, any instrument windows from previous projects will not open. FX plugins and midi processors open fine; it's just instruments. If I try to load a new one, it opens fine, but I'm unable to open the instrument windows of any previous projects. I tried trashing preferences, restarting, etc. Nothing. So I rolled back to Logic 11.1.2 and everything works now. I hope Apple can fix this bug asap.
Another unrelated issue for those of us who use the C24 control surface thru the VControl software by Neyrinck.com is that the system constantly loses communication in one direction. This happened since Logic was updated to version 11.1.2. Neyrinck has confirmed this to be a Logic bug. They have informed Apple about this, but have received no reply. Apple, please address this!