Video not going through in some location

When I am at my mother’s home connected via her wifi network, if I make a call from an Android phone (latest Jami from F-Droid) to her iphone, the video works. If I do the call from my home, the voice works but not the video. With Jitsi in a call with 2 people only (p2p is enabled) I noticed exactly the same issue. We both have a fiber connection, so throughput it unlikely to be the problem.

On my Android phone, I see TURN is enabled with, but perhaps that server is a bit far (I am in Europe). STUN is disabled. On iPhone, I don’t see any such option.

My mother has CGNAT with IPv4 and IPv6, I have a public (and static) IPv4 address, no IPv6. Is there a way to make the P2P video work when she is at her place and I am at mine?