rear windshield wiper not making full contact?

[beamertruck]

Soo as the title states the rear windshield wiper isnt making full contact, i tried white liithium, afterwards tried PB blast which made a bit of a difference, gone through 3 wiper blades to see if maybe its the blade. I may try replacing the arm, its just weird because it makes full contact up until the left side of the windshield where it only wpes the inner part of the windshield. Not a huge deal but it is kinda annoying.