iMessage over PIA VPN

Hi,

I'm having trouble receiving iMessages on my 2020 M1 MBA with Ventura, when connected to my PIA VPN. When disconnecting from the VPN they work fine. Private home network.

In order to aid in troubleshooting can someone please point me in the right direction of the ports and addresses used in iMessage communication or a reliable method of testing the connection?

I found If you use FaceTime and iMessage behind a firewall - Apple Support, but it doesn't reference any addresses so I can't curl to them, and there are many to test.

I'd like to curl to a specific port and address, but I can't find any reliable public information on the addresses or ports Apple use for iMessage, and I'd rather not crack out Wireshark to sniff the network traffic just now.

Many thanks.