Brewed 10 gal of a German ALT, which came out perfect for Alt. Problem is the beer just seems a little boring now and I am only about 1/2 way through it.
Your beer might be getting stale, early stages of oxidation/aging are characterized by a generally "dull" profile - fewer esters, and less hop aroma and flavor, plus hints of chemical bitterness and/or honey-like notes. Drink the last of the first keg first or use the remains of that keg for cooking.
If you can, keep the other keg as cool as possible to minimize oxidation.
Adding dry hops couldn't hurt to bring up the hop aroma, especially if you're worried that second cask might be getting oxidized, too. A Cascade dry-hopped alt sounds interesting.
Just make sure that you put your dry hops in a bag so you can easily get the hops out. Otherwise, you'll be picking up a lot of hoppy trub and might have problems with the pickup tube getting clogged.