Couldn't find a similar problem listed, perhaps it's just a case of a quick tune in ports/blocked lists...?
Anyway, here it is: have a working NAS server with OMV running on an Odroid HC2 since last year; and two weeks ago I've added to my network a PiHole, running on a Pi zero W2 (with usb Ethernet). So it's not the case of OMV and Pihole running on the same machine and address: two different machines on two different addresses.
Both the NAS and the PiHole are working well, but since installation of the latter I can't access the web GUI page of OMV. What I get is:
" This page isn’t working
192.168.1.228 is currently unable to handle this request.
HTTP ERROR 500"
Even though the server works just as before, and I can SSH it just as before.
There's no problem in access the web GUI or SSH in the PiHole.
FWIW, I've added "192.168.1.228" in the whitelist, with no results.
Thanks in advance!