Honestly, it depends on the guide, but generally, spirit guides are said to be here to help your soul evolve. If they put obstacles in your way, it is because you are supposed to learn something from them to help you grow.
I always find it funny , though, how black magicians will place blame on spirit guides for their lives going to pot, but will then turn around and lap it up if someone says Belial, Azazel, or Lucifer made their lives hell but they’re now stronger because of it.
I agree with @UnseelieDiabolus Sometimes, shit happens. However, if you want to know if there is a spiritual cause, try divination.