Hi, the same here (and same environment Dspace 7.6 and Ubuntu 22.04)
It was working fine until yesterday and today, users started to complain

(in the submit page)
Assetstore appears to be fine (and owned by tomcat user), i can still access old items files via dspace
I've checked /var/log/tomcat9/catalina,out, /opt/dspace7/install/log/dspace.log and pm2 logs
This is the only error messages I see
Our OAI pages shows error 500 but i couldn't find the cause
I've already rebooted the server, restarted tomcat and made a "pm2 stop / pm2 start", mvn package but no success
Any tips?
Thank you very much and sorry for english mistakes, lol