Hello,
Don’t edit the database yourself… Try occ command before. You can find this here :
https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/occ_command.html#maintenance-commands-label
You can try :
sudo -u www-data php occ maintenance:repair
sudo -u www-data php occ db:add-missing-indices
If it doesnt work, look at this :
Good luck