App using wrong DNS server

OK, so I'd been having some issues with my primary NAS informing the others regadring the UPS status.  While it does seem to have worked itself out, I decided to see how well the Eaton Intelligent Power Protector (IPP) does on the NAS.  I tried first on one of the secondary NASes, since I also have a Windows box with another Eaton and runnin IPP that could serve as the host until I decided whether to install it on the primary NAS..

 

The installation from .deb file went without a hitch.  But then things got squirrly.  Instead of finding the host system at it's local address of 192.168.0.6 (as has my secondary Windows system), it found it at 198.105.254.228.  I understand that to be an IP some DNS servers assign to an unresolved name.  But that would mean it was using my IP's DNS server, not my router, which is clearly shown as the DNS server in the Network settings of the NAS.

 

So, I unplugged my modem from my router and, sure enough, the software found the host IPP system at the right address.  So, I set everything up so I could test the shut-down.  But somewhere along the line, I did plug my modem back into my router, and the IPP software lost contact with the host.  Unplugging the the modem again restored the connection.  Clearly, it's using the external DNS server, not my router's, when that server is available.

 

Thinking ZeroTier may have something to do with it, I disabled that.  No effect.

 

While I have contacted Eaton regarding this matter, I wonder if it isn't something about the NAS configuration that's causing the problem.  Has anybody seen anything like this. or have any ideas of what I might try?

 

I really like the additional info IPP gives me about the UPS, so I'll probably still install it on the primary NAS.  But I'd like to use it for the secondatry ones, too, as it has more shut-down options.  And, yes, the shut-down does work well, at least run as a test.