I have the v15 service started and listening on 0.0.0.0:5434.
Through TCPView, I can see it listening on 5434, I can see the previous version listening and connecting on 5432.
I can connect from localhost to port 5434.
I have ipv6 turned off in the network settings on both machines.
From any other client or server, I get
"Are you sure the server is running on 192.168.1.112 and accepting connections on 5434?
The relevant line in pg_hba.conf looks like:
host all all 192.168.1.0/24 password
I can't see what else I'm missing.