I mostly get timing issues with subtitles if I’m using the embedded ones for some reason. Choose some on the pane at the left of the subtitles popup beneath the “embedded”. In my experience, the first one is usually perfect. But you can scroll through till you find one.
And pro tip: play around with different cached files – so instead of choosing (say) the first of the cached files in the results pane for an episode/movie, choose the next one down (as long as it’s the right quality for you, usually 1080p). If it’s a series, the next episode will automatically play from the releaser of that cached file if it’s in the list.