White grout after seal?!

Here are a few pictures that a customer sent me. We cleaned and sealed yesterday and she said there are lots of areas where the grout looks like it should (how she remembers it when it was installed a few years back) and other areas where it is white.

We used Stonepro pro sealer and I am thinking we may have over applied the sealer. She said that it wasn't coming off with a damp towel.

Any ideas?

@Blacktiedetailing
@Stone Pro
@Lance...

White grout after seal?!