That's common. The bike will behave differently under load. Do you have a trainer? Sometimes I will work on tuning with my bike set up on the trainer with light resistance (enough that I can still hand pedal, but not so little that it's freely spinning).

Because you are getting stuck shifting in EITHER direction, it's probably a cable issue instead of a FD adjustment. Try lubing the cable well under the BB with any oily cleaning lube like Prolink. Lube/clean the shifter with WD-40. Have you always had this problem? How old are your cables? You might need new ones.