Fail to sync Joplin App on Nextcloud as WebDav-Connection

The Synchronisation does’t work with Nextcloud. If i configure Dropbox, everything is fine.

There ist a server in my privat net runnung on LXC Container Debian Buster on a host with Debian Buster over DDDNSS.de and everythings good.

Davfs is installed and activated in Apache.

Sometime during sync test from Joplin the whole Server ist crashing. With “only” Nextcloud, without Joplin Connection it runs days and weeks without any problem.

What Logs do you need to check the Webdav functionality of Nextcloud?
I would be very happy about your help.

Regards
Sven

Nextcloud 21.0.1 running

more details needed - what does it mean “whole server” crashes? OS level, Webserver? What happens exactly - does it restart, reboot. Do you need to perfrorm some action to recover? Do you see something in Joplin logs?

I run Joplin against NC (19 and 21) on docker for a while now without visible issues.