welcome to the forum,
that allows for over-mounting. should not use unless 1000% sure you need it.
tho, odds are that is not the issue.
other then that, not seeing any issue with the mount command.
tho, i do not recommend using it in production, rclone has the smb remote.
might try testing with that.
check out my howto guide about smb
just curious, why use complex rclone mount, instead of simple rclone copy|move