Once the water dries, can you still see the area? If so, the sealer is not keeping out the water. All stone is porous, but adequate sealing should keep water from getting to the stone.

Yes, it's the black shady area above in photo. I've had it sealed TWICE and this keeps happening. I'm not getting what some have described as mineral stains, such as from a wet bottom of a glass. I don't know what to do next. Keep complaining? Demand my money back?

Is he using a topical or impregnating type of sealer?

Topical I assume. It was applied with cloths second time.

First off, call the granite provider (the person you bought it off of) and ask the name (and version) of the product that was used to seal your granite.

I would take that knowledge and contact a third party (like another stone/granite provider) and ask them about kashmire granite, the best "sealant" options and what causes water stains (ie. what chemical sealant will typically allow water stains vs. ones that don't).

Compare the two answers you receive. The third party should offer non-biased advice. The 'provider' should give you the name of the product applied to your stone. Now you have enough information to work with.

It is very possible this is a natural tendency of some granites to do this. It is also possible to slow down this type of staining with the appropriate product. The question becomes, "Did you receive the appropriate product from your stone provider?"