@Itmsthank you for your reply. I tried qbittorrent and transmission on macOS. I explicitly open the IPv6 port on my router (only reachable over IPv6 on the internet, but have dual stack at home), Transmission says the port is open, but it looks like nothing seems to be going out. I am seeing some pairs trying to connect, so I guess this is not a problem from the tracker neither.
Thank you anyway!
For what I can tell he's just shift clicking super fast. (you can hear the multiple answers from the unit)
EDIT: if you are wondering how he place houses without resources is because in a23 Ptol houses were free