How long has it been like that? I've been torrenting via Mullvad for a while and occasionally low-seed torrents take a while to initialize but eventually I get them. Sometimes it means thinking ahead a few days for media that's more niche.
Mullvad did away with port forwarding about 1.5 years ago. https://mullvad.net/en/blog/removing-the-support-for-forward.... If im not mistaken its not your ability to download the torrents that is effected but your ability to really upload the torrents. If you belong to a private tracker with a strict seeding to downloading ratio i would use another VPN service for that
If a torrent has no seed with an open port, a peer without an open port won't be able to download.
This means having no port-forwarding shouldn't be much of an issue on private trackers (because most people have it to improve their ability to seed) but on public trackers some torrents might not download.
Unless you were actively using port forwarding before it wouldn't be any different. If you need a VPN for your torrents, despite these faults I don't know of a better one myself. I use the Firefox VPN (which is Mullvad under the hood and it's worked at least as well if not better than any alternatives for me so far.
