Using Transmission 4.0.5 on Mint 22.2.

I've been running a seedbox for some time now but have never made a new torrent before. I've got a file I want to make publicly available but for some reason can't seed it normally.

On the seedbox, Transmission is bound to an open port, and I added the best 20 trackers from this repo to the torrent. I also have a client I'm trying to test uploading to, but it can't seem to connect to the seedbox unless I also open the port on the leech client. Once I do it works normally, but I was under the impression only the seeder needed to be on an open port in order for clients to connect. Am I wrong and it's expected that both seeder and leecher have open ports? Would really appreciate some help!

GitHub - ngosang/trackerslist: Updated list of public BitTorrent trackers

Updated list of public BitTorrent trackers. Contribute to ngosang/trackerslist development by creating an account on GitHub.

^GitHub