One of two NAS will not mount after 3.0 update

I have two Zyxel 325 v2. Both are configured exactly the same and have been working fine with no problem what so ever for years with 2.xx. Updated to 3.233 today and Volumio only mounts one of the two NAS??? Trying to mount the missing NAS results in “(112) Host is down”.

I have searched the “Volumio 3 FAQ” but didn’t find a relevant solution, besides downgrading to 2.xx.

Both volumes mount without problems on any of my other computers, mount and respond to ping from the same Pi booted from a Raspian microSD card.

So, what to do besides downgrading???

BTW, With full-time job, family with four kids, I don’t have hours to spend on fixing this, so easy fixes are appreciated.