Glad to hear it’s working! We’re taking a look to see if there’s something weird going on with Flycast routing on your host.
The main difference between .internal and .flycast addresses is that requests over .flycast go through the proxy while .internal are direct to the instance. With flycast you get some extra goodies from the proxy (like load balancing) but for the most part you shouldn’t see a big difference. Full details on the difference between the two are here: Flycast for postgres