the raspberry running haos is connected to the satellite, then the satellite goes offline (i.e a restart). when the satellite is up again the raspberry will reconnect, the ha frontend is now unreacheable.
at this point i need to restart the main router too... haos network is configured on auto.
You mentioned that HAOS network settings is configured on auto? Don't recommend that. Either assign a static-IP in the network settings of HAOS that are outside the DHCP range or use DHCP reservation on your router to assign a static-IP. If I had to guess, this is why you're having issues trying to access HAOS frontend right now.