I have a mushy, wet mulch question from my new beautiful lawn?

I used TAGRO and mixed it with my nice Puyallup Valley soil. The lawn is absolutely beautiful! The problem is that it is growing almost faster then I can keep up with mowing. The problem I have is that if I don't mow it then it gets too long too quick and then it is harder to mow. The real problem is when I mow the grass does not go up into the bag but turns to green lawn mush and sucks up into the underside of the mower! I make a couple two or three passes and have to take it to the side, raise the front and spray the really wet, really mushy mulch out from under the lawn mower.... I try to wait for dry lawn and it has had three day no rain or watering times, but it still just mushes up into the mower? Is it that it is new lawn? Do I need a new blade? I have a decent mower that runs well with the exception that it starts bogging down with the wet mushy mulch that starts to impede the blade. Any ideas? Absolutely love the lawn and wouldn't trade the way I have to mow if that is what it takes, but if there is an answer? I sure would like to know? Thanks for any help or advice I could get. Respectfully, Diane Lyn