Man that sucks. I must have gotten lucky or something with my setup. I also have trackers go unavailable all the time but I enabled 8 different ones and usually multiple will have the same torrent so it usually has no problem finding something even if 1 or 2 are down. I also don’t VPN tracker searches, just my BitTorrent client so flaresolverr seems to work fine for me (I only have it enabled for 2 of my trackers since most of the ones I use don’t seem to require it).
If you end up trying it out again I would look into the quality settings and make sure you’re not using the remux quality profile (edit: apparently the default 1080p quality profile has the 1080 remux quality enabled so this might have been the problem). By default most of the quality profiles seem to limit at 100MB/min, so a 2 hr movie shouldn’t allow anything over like 12GB. Whenever I tweak quality or custom formats I refer to trash guides which has a lot of battle-tested rules you can copy. I have my main quality profile set to only download qualities between hdtv720 and br1080 (which is just below remux) with custom formats copied from trash guides set to prefer hevc with surround sound since I have 5.1.