[Milhouse]

edit 2: I see a 1 minute 20 second timeout every time there's a RPC connection established with IPv4, just not sure what's causing it.

Yes, establishing the rpc connection seems to be the problem. Setting @rpc.ipversion=4 would fix the issue.

The default script behaviour is to try and establish an IPv6 connection first, then fall back on IPv4.

The script uses a short connection timeout initially (when the script is initialising), which would explain why you're able to establish an IPv4 connection fairly quickly at the beginning, but subsequent connections don't specify a timeout (using the system default timeout) and connections take much longer to establish as it's taking 80 seconds for the initial IPv6 connection to timeout.

I've pushed a fix (v1.8.9) which will re-use the same IP version once the first rpc connection is established, so you should automatically use IPv4 for all connections.

As to why IPv6 connection are taking so long to fail on your network is anyone's guess, maybe a network configuration/router issue.