Cool, enjoy

My guess is that your issue is from torrentio, I don’t use it but heard a lot recently about instability. You could try comet instead of others.

You already had some good advices but something I haven’t seen mentioned. If you use Kodi (and probably a couple others media player), you could use some sub plugin like open subtitle (forgot other names) to fetch subtitles on the fly when you will play video. It can be hit or miss at first, but subtitles name are like release name (title, quality, release group). So if you often encounter a release group that do your sub language. Try to download video from same release group, so you will have better chance that audio/sub sync properly.

This apart, +1 for private tracker as already mentioned, you may need some searching to find one but worth it.