Every bag I have ever purchased has been "wet".
I have never had good luck dissolving it no matter how long I wait or what method I use. There are always a lot of white crystals left that will never dissolve. The final mix always needed a good bit of tweaking to get to my target SG.
With my system, pH was harder to maintain when I used RC salt, and I never noticed much of a boost in the calcium level. I guess that might explain the white crystals.
I had to switch back to IO salt. Had enough of RC.
All that being said, I never had any serious problems with it after I finally got it into the tank. I just seem to have an easier time with IO salt.