The top spring loaded part that is housed in the slide, just below the rear sight, is the firing pin stopper. (Safety feature to keep the firing pin from striking the primer when trigger is not actuated.) The trigger bar is supposed to raise that part to a full clearance point so that the blocker is never interacting w/ the firing pin during normal use.

More likely what's happening is that trigger bar component designed to disengage the stopper is wearing down (or otherwise being displaced), causing the firing pin to hit a little bit of the blocker during normal firing actuations, as a result of the stopper not being fully cleared. This would, of course lead to undue stress being applied to the firing pin, in that break point area, too often and ultimately leading to the break.

P.S. I also posted this info on your video listed above.

You can check for proper blocker clearance by taking the hammer out, putting pistol back together & manually pushing the firing pin forward while holding trigger back. The pin should move forward w/o any resistance, if you feel resistance, then the blocker is not being cleared properly.