Hello @DTC57
I used this link How to install ONLYOFFICE in Nextcloud Hub - Nextcloud to install Community Edition.
This is not our product. A few years ago Nextcloud team forked old version of Document server and changed its source code. We have description of the situation here: Community Document Server app in Nextcloud 18
We always recommend to use official guides and products: Installation Guides - Docs Community Edition - ONLYOFFICE
I cannot troubleshoot your installation or provide any guarantees of stable work, because we did not create this version of the app. If you are going to use Document server with Nextcloud, I would recommend to take a look at official guides and follow them.