Got mine today too. Question for you:
Instructions say, p. 2, that “The handle will remain fixed in this position”. So, I found “locking” keeps the diagonal-ish of the handle is fixed by one of the half-dozen or so slots. BUT, the handle still can swivel.
Is your handle COMPLETELY fixed and locked in operation?
I’m wondering if my unit has some problem with the axles of the handle within the unit preventing it from being absolutely fixed.