Yep, you were right as well. But I’m happy to have gone a bit deeper into the issue… There’s always something to learn.
Thank you all for your patience! 
When there’s time, I’ll take the wiki tutorial by @bmillham (Configuring fstab based Samba share mounts) as a basis for a slightly changed second one for fstab based NFS share mounts, if that’s ok with him…