OK. This may very well be the problem.
I've noticed, too, that my Dynon used to always have the altimeter setting somewhat near normal when I cranked up the airplane--maybe the last setting but I never noticed--now it seems to always be set to something reading about 2000-3000 feet HIGHER than field elevation. Could that be the same issue?
Columbus, TX (66R)
RV-8A, purchased flying
Cessna 150F; Beech Baron B55