Nextcloud and SMB on Windows server


I am having issues integrating External Storage - Local with a mount to a windows server share. This used to work with NFS mounted to a TrueNAS NFS share, but now trying to do it with SMB.

I am on Ubuntu Server 22.04.2, Nextcloud 27.0.0 Hub 5, no Docker.
Not joined the windows domain.

Configuration as follows:
SMB Mount /mnt/Photos to a windows SMB share on a normal windows file server.
In Nextcloud using External Storage app with configuration “Local”, allowed Read/Write for all users.

Nextcloud can’t create folders or files in the folder Photos.

I thought of giving /mnt/Photos www-data permissions, however even if I do that prior to mounting, they will revert to root:root when I mount the folder.

At this point, I am not really sure where it fails. I can create folders in the shell, so permission-wise it’s OK. However, not from the standpoint of the webserver apparently, who would I think need www-data.
I am also not sure which user is used in the Nextcloud website, when I try to write to “Photos” (which is a /mnt/Photos mount to windows server).

I want to avoid NFS due to permission issues with NTFS, I would hope it works better with SMB.
I want to use Local, as that ensures that I’m always up to date, kind of live folder if you will.

How would I go about solving that?

Thank you