You might have irritated your ulnar nerve on the arm rests. Once that nerve gets going, it’s hard to settle down, especially if you keep doing the irritating thing. Typing on the computer, elbows on the lunch table, or even sleeping on the wrong side can cause issues with the nerves and tendons in the hands, elbows, forearms, and such.

Or you might have a nerve that slips in and out of its designated path, thus certain movements need to be avoided until things settle down, and then be wary of those movements. Some folks have to position the elbow on the rest, squirm around just a bit to make sure the nerve is not impinged, then have at it. After a few flights, they don't even think about it anymore and don't have problems.

A good sports medicine doc should be able to get the irritated part sorted out and get you on the right road to recovery.