Nextcloud data folder rights keep changing

I have a linux vm on a hyper-v server on a windows server running nextcloud. I tried to backup the user data from the host machine (the windows one) via a samba share from the linux system. As I did this using a different user I had to set chmod -R +xr nextcloud-data to access the files. Seemingly randomly the rights are reset to where other users don’t have any access to the folders.
Is that some kind of nextcloud feature? If not any idea where this comes from?

This may be beyond the scope of this forum but does someone know a good way to backup data outside a vm if nextcloud runs in one?

Can’t you create a smb-access for the backup process on your windows machine? Everybody authenticates via smb?