SXR80 and SXS80 ethernet backhaul via 1Gb hub/switch not working

Hello,

I am unable to connect SXR80 and SXS80 via 1Gb ethernet hub.

topology:

( cellar: modem)->(other room: router)->(cellar:hub)->(yet other room: satellite)

When connected directly it works, but such setup is useless for us as we have fiber connection in other room and only 2 ethernet cables going from modem/to the hub which handles other wired devices. Building is made of stone so wireless backhaul connection speed is way too low (sub 200Mb) and ping went up from sub 1ms to 5-10ms.

Is there anything that could fix it except buying another satellite to avoid back cable to the hub/modem box? This seems to be such basic requirement and I cannot believe developrs do not realize that backhaul via hub is essential functionality.

Thanks