True, most seem to have units that are collimated to the point where are quite usable. And, for the relatively low cost, it’s a good deal, especially for those first trying binoviewing. The world of low cost, mass produced goods does have some lemons get out the door, as to be expected.
But I glad you found the reason some units just don’t work. There is a possible cause other than the eyepieces not being aligned.