Oh, now I got it. Sorry, the information about our connector version confused me earlier. Please note if you are using Community Document Server app that you should know that it’s not our app. We have a description here: Community Document Server app in Nextcloud 18
So yes, please deploy standalone Document server and use our official connector to integrate it with your Nextcloud ONLYOFFICE - Apps - App Store - Nextcloud
After that please check the situation again.