After day long operation: Cannot create "data" directory

Dear all,

I have a problem that I cannot manage to resolve, as I cannot get the pattern.
I have a Nextcloud running in a docker on Raspberry Pi.
It works well for quite some time (a day long), then it falls into ‘Cannot create “data” directory error’. The /data folder is a samba network drive mounted to the Raspberry Pi (and mounted to docker as a volume), fstab of Raspberry:

//192.168.2.1/intenso  /mnt/netdrive  cifs  username=user,password=,uid=user,gid=user,_netdev,x-systemd.automount,auto  0  0

When the problem occurs, I get question marks when request info on the ownership , CLI in the container under root:
image

Interestingly, either restart of the container or very simple cd into the directory, i.e. cd /data resolves the problem. The data is available and the ownership appears:
image

Has someone had an issue similar to that? Any idea/suggestion?

I suppose now that the mounted drive goes in a kind of idle mode. Try to play with mounting parameters.

Bests,