BMbikerider, I had a very similar problem with Fuji Crystal Archive MP way back in 2006. Have a look at the my thread" Fuji Crystal Archive MP and Yellow Filtration". My paper was the MP type and not what you are using but like your problem, mine came out of the blue as it were like yours and the filtration decrease in Y had not been experienced before.

Although I make no mention in that thread of the outcome I think I can recall contacting the retailer who asked for an example print with filtrations on the back. The retailer never admitted that the paper was at fault but did replace it and on later prints from other films the issue disappeared.

However I cannot rule out a problem for definite with the films used. See PE's comments in the thread