Reargate does not open

Hi, on my V40 Kombi from Bj.01 the tailgate does not open any more. Had been hooked more often since recently, then it went up at some point, since 2 days nothing happens anymore. How far can the lock be turned? On my can it turn only 90°. I sprayed in W40 once. Should I then spray some more Teflon Spray or similar?