First, let me give appreciation for OMV. Great system and I've really enjoyed using it, and showing it to others. Thanks for all your hard work!
I have DNS set up my network and omv.mylocaldomain..com set for the server. It navigates to it with no issue, and this DNS information is also set into the OMV server. I have not had any issue with it for the last several years. Now, however, if I navigate to the server with the DNS name it goes to the login page as usual, but will not let me log in. Gives a 400 error "Incorrect username or password". I navigate to it via it's IP and type in the exact same credentials and it logs me in just fine.
Checking the logs, it shows one attempt with a bad usr/pwd and then shows logging in working. Both have the source IP of my local machine as the same. The only difference is that on the first try I have http://omv.mylocaldomain.com in the navigation bar and on the next it shows http://192.168.1.36 in the bar (neither are the actual names/IPs).
Any ideas on why this is happening? It only started in the last month or so.