delta faucet

I've been gone a long time ,things have changed on this forum.
I don't know if this is the right place to be, but here goes.

I just changed a cartridge in my shower, It's a delta temp control unit.
The water pressure has dropped a lot.
there is no blockage in the screens or restrictors.
could some thing have lodged in the temp. mixing valve?

If this post gets thru, I'll be surprised.
Anhoo, Thanks