SharePlay is not working

I am trying to use SharePlay to listen to music with my brother over FaceTime but although my device will say I am sharing my music, my brother doesn’t hear anything from his end. When he shares from his phone I similarly don’t hear anything. I also don’t receive any indicator that he is trying g to share his music. We have similar troubles when trying to screen share and share play videos.

we have checked settings, iOS, app versions, and anything else we could think of.

the only other issue I can think of is that I am living abroad and use a foreign network provider. That said we always use WiFi calling and we have tried messing around with a vpn as well, but it hasn’t changed anything.

Is there anything we can do to fix it?