can't access postgresql database on computer with two networks?

I am trying to connect to a postgres database that resides on a debian server. My computer where Power BI resides is a windows 10.

The Debian computer has two different networks (two different ethernet ports).  a 192.168.1.0 network and a 172.16.50.0 network.

If the 172 network is disconnected, I can access the database just fine and connect to most of the tables (three don't show up).

If both networks are up (as they NEED to be), I can't access the database at all. 

I've added all the appropriate permissions in the pg_hba.conf file, I've opened up the ports on the debian, I've added the debian computer (both IPs) to the Windows hosts file. 

I'm at a loss -any ideas of what needs to be done or something I could try? I'm not sure why Power BI is having issues connecting with both IPs to begin with. ANY kind of insight would be greatly appreciated! 

Thanks in advance!