Unable to access files from nfs/smb mount on Ubuntu

Ubuntu 20.04 mounts a NAS folder to /home/simon/Documents via NFS or SMB/CIFS.
Files can be seen & opened from Nautilus & the terminal without any issues.

LibreOffice7.1.3.2 is unable to access this folder… it says permission denied.

If I mount the NAS share via NFS or SMB/CIFS to new folder eg /home/simon/docs, LO cannot access it.
If I mount the NAS folder to via NFS or SMB/CIFS /mnt/Docs, LO can see & open files without any problems.
LO is also unable to access any network device via the “connect to server” from "other locations. The “connect” button is greyed out.