pvc front door lock wink haus cant fully lock from inside loose handle?

wink haus 3 hook 2 slider lock on pvc front door,from the outside you can pull shut and then push up handle and fully lock the 5 way locks.
but from the inside when you push up the handle its completely loose and free and not locking the the 5 locks and the key wont turn to lock .you can push close the door and pull down the handle to open its fine .
can i change the middle lock of this 5 way system ? or do you have to buy the whole 5 way door lock ? and do you have to replace the euro lock barrel ?