Connection problems between a home assistant and a PC


I have my home assistant OS on a raspberry pi 4 working properly. I also have a PC with OpenMediaVault and docker working properly.

In short, I can’t make connections between the raspberry and my pc. Each can connect to other things like cameras but not each other.

My idea is to have the frigate addon running on the pc and connect the Raspberry but it never worked.
Frigate also failed to connect to the Raspberry’s MQTT.

The last thing, I connect to my VPN installed on the PC and cannot see my home assistant.

I don’t know if I have a configuration problem with the router, with my home assistant or my OMV.

Previously I had my home assistant on the Raspberry pi with docker and I had the same result.

Someone help me?