Docker and dual NIC cards

Hello All-

My Supermicro server has dual NIC cards. I recently reconfigured the network settings not to use bonding, so I have br0 and br1. In the docker settings I set "IPv4 custom network on interface br1:"  to Subnet: 192.168.1.0/24 Gateway: 192.168.1.1 DHCP pool: 192.168.1.128/25  (128 hosts).

I installed a LetsEncrypt container at 192.168.1.130 and it works without any issues,  and I was able to set my router so that https://<external ip> is routed to the container. 

I wanted to use the SABnzbd container on 192.168.1.150, so I reconfigured it and it started up fine and I was able to connect to the container at http://192.168.1.150:8080.  I ran into an issue at that point: none of my other containers (NZBHydra, Radarr, Sonarr, etc) was able to connect to the SABnzbd container.  After some experimentation, I discovered if I reconfigured a container, say NZBHydra, to use an IP like 192.168.1.140, that it was able to connect properly.

Is this expected behavior, or is there some routing rule I need to set to make this work?  I recall reading something about some limitations using dual NIC container, but haven't been able to find details.