DotNet app can't create subfolder in mounted samba share

Hi all

I am hoping for a bit of direction in troubleshooting this strange problem with a DotNetCore app running inside a LXD container.

I have a samba server “ComputerA” sharing /data/uploads to the vlan

mounted over the vlan on “ComputerB” with cifs at: /mnt/uploads

mapped into a LXD container on ComputerB as: /uploads with:

lxc config device add "$CONTAINER_ID" uploads disk source=/mnt/uploads/ path=/uploads/

LXD Version = 4.24
Host system = Ubuntu 20.04.4 LTS
Container Image = debian/11/amd64

I can create and delete files/folders inside uploads/ from both the host (ComputerB) and the container simply and easily

also in the container is a DotNetCore6 application that wants to create a new subdirectory under /uploads/newdir but it is unable to.

Error message from the app:
Attempt --- Add Folder:: /uploads/newdir","Attempt --- Create Inner File Folder","Attempt --- Is Success:: False

We interact with the DotNet app through a web interface (NginX in the host reverse proxies to the app in the container)

I see nothing in the syslog, samba log, nginx log or application log to explain why the app is unable to create a new folder.

Here is the fstab entry on ComputerB where the samba share is mounted (the uid/gid is that of the user inside the container that the app runs as):

// /mnt/uploads cifs _netdev,username=XXXXXX,password=XXXXXXX,uid=1001000,gid=1001000,rw,user,noperm 0 0

I don’t know what other information I can provide, and I have no idea what to look for.

Any thoughts or ideas are welcome?