Unsolved UBports forum and apn ipv6 protocol

[domubpkm]

Is the forum optimized for the apn ipv6 protocol ?

In use under android aosp (Volla OS) and any browser used, I find that the time to open the first time https://forums.ubports.com/recent is particularly long (when the page wants to open) compared to other sites that open much faster in ipv6.

if I close the browser and open the forum page again, same problem again.

The forum opens quickly with the ipv4 protocol.