Nextcloud Office disabled from time to time

Hi, I am using NC23.0 and also Nextcloud Office which works fine. But from time to time customers reports that when they click an office document, a download option is shown instead of presenting the document. I then have to go to settings → Office where “Use your own Built-In CODe Edition” is active, klick again on that Option, and then documents are opened again. It seems that the used built-In App is shutdown from time to time.
How can I change this behaviour and make the Office plugin available all the time?