Admin access in IP-Passthrough mode

Hi, long time lurker, first time poster.

I have a Max BR1 Mk2 running in IP passthrough mode, SIM working and its LAN port connected to Secondary (failover) WAN port of a UniFi UDMPro.

The internet connection failover is working well.

I would like to be able to manage the BR1 from the LAN side of the UDMPro router, but I am getting no response to http or https requests on

I did try setting a static route for that IP out tothe UDMPro interface that it is connected to, but no luck.

Does anyone have a similar scenario and could offer suggestions?