Hello @EasyOneX
Please note that Community Document Server is an app developed by Nextcloud. With that said, we cannot guarantee stable functioning of this app and you should to contact Nextcloud support with detailed description of the problem or try looking for the advise on their forum: https://help.nextcloud.com/
Some additional information you can also find here:
If you decide to install ONLYOFFICE Docs (Document Server) on a dedicated server, you can visit this page to find official guides on that:
https://helpcenter.onlyoffice.com/installation/docs-community-index.aspx