I think that may be a common experience. Mine usually stick hard initially too. I have found that if I give the pull handle a hard "push" first, before "pulling" it helps break the glue sticking experience.
Sometimes, they initially pull so hard, I can only pull them slightly. Then I push them (hard) closed again, and do another pull. Usually the second "pull" will let me pull them all the way open.
I figure, it's just "stuff" hardening to the inside of the valve slide that causes this to happen.
2019 Montana High Country 375FL
2014 Chevy Duramax HD 6.6 - 3500 Diesel Dully Long bed Crew Cab