Subtitles don't match dialogue

Just commenting: I’m watching Netflix in Spanish with Spanish subtitles. The words used in the soundtrack are substantially different than the subtitles. The English subtitles are closer to what is spoken than the Spanish subtitles.

This is common problem, even with native Spanish programs. Apparently there are legal issues with simply supplying unauthorized matching subtitles. However, some will match much better.
For instance: Her Mother’s Killer, Silvana Sin Lana, and Gran Hotel are much better. You just have to try programs and see. Alta Mar subtitles don’t match well. Hulu has Blood Bloods en Espanol, Elementary en Espanol with 99.8% correct matches, but they are dubbed, if that matters. And the Hulu interface is far behind LLN.

As already noted, this is common. If you want subtitles to match, generally you need to watch shows/movies where Spanish is the original language. Dubbed content almost never matches (although you can get lucky sometimes, as @Jim mentions).