That is a common problem. All of my scopes have the fast-focus tightened down against one, two, or three O-rings. I do it even if there is no apparent wobble in the eyepiece, as it also keeps the fast-focus in the position I like."addertooth"I had a cheap scope which had a side to side mobile eyepiece, but other than that it worked well. I stacked O-Rings on the threaded portion to eliminate side to side slop, and my reticle became solid. Cheap fix to a common cheap scope problem.
It should not shift anything like the degree shown here, whatever the alignment. The sight picture was clear edge to edge so alignment can't have been bad. Plus the camera is fixed so the point about head bobbing is moot. Joe is pretty experienced and his other videos of other scopes show nothing like the degree of shift he's demonstrating here, so I think a schoolboy error on his part is unlikely."Scotchmo"Joe,
Adjusting until out of focus introduces parallax errors. On the Monstrum test, the camera was not likely centered when you were changing the focus (parallax). Hence the apparent shift.
That problem exists in just about every variable-mag/high-quality/high-mag scope. Turn the magnification to the lowest setting. View a 25 yard target. Adjust the focus until it is blurry. Move your head side to side. I would be surprised if you do not see a big change in POA. If you center your eye (or camera) perfectly, you will be able to adjust the focus in and out with no change in POA.
I've got a Monstrum scope. I'm still evaluating it. It's got some issues. But why call it a POS for a known problem that is present in most every similar spec scope?