new Pixel 4XL as host, "allow" remote immediately disconnects

I connect to my friend's Pixel 4XL

He sees my request, hits "allow"

and the connection is closed

on my end, the pop says my request was denied.

We know how TV works, beause I can remote into his PC, and from his PC and phone, he can remote into my PC and phone.

It's just his phone that neither he nor I can establish connection into