I present an alternative way to use Pi-hole outside the home network by leveraging Encrypted DNS (aka DNS-over-TLS and DNS-over-HTTPS) instead of the usual VPN.
From my understanding, it only checks DNS when it initially connects, and so if the public IP changes the connection just stops working.
This is pretty standard TCP network behavior for long duration connections. The client queries dns for the IP address, opens a socket, and leaves it open as long as needed.
One thing that would help here is some kind of keepalive feature, like a client to server TCP connect or SYN, or better yet a higher level protocol signal. Check your client to see if there is some tunable keepalive. It may be set so something long like 1h.
This is pretty standard TCP network behavior for long duration connections. The client queries dns for the IP address, opens a socket, and leaves it open as long as needed.
One thing that would help here is some kind of keepalive feature, like a client to server TCP connect or SYN, or better yet a higher level protocol signal. Check your client to see if there is some tunable keepalive. It may be set so something long like 1h.
Wireguard uses UDP, by the way.
https://www.wireguard.com/protocol/
Wireguard does have a KeepAlive option, but I found it didn’t seem to help in practice.
Could be bugs with the client, which is pretty barebones.