Not all are that bad, but I can't say this is uncommon. There are several different mods you can do to dramatically reduce it. Not all BLB has the exact same root cause. Sometimes it's the plastic bezel/housing, sometimes it's the metal frame, sometimes it's just how the panel got seated in the housing, sometimes it's a mixture, etc...it can vary.
I completely removed the plastic bezel/housing and used an epoxy weld to attach the circuit board and VESA mount to the back of the metal panel frame. That helped a lot, but it's still not quite perfect. I'd probably need to dismantle the metal panel frame and bend it into better form to entirely fix it, but it's just not worth it at this point. Mine was still not nearly that bad completely stock, though.
The QNIX monitors are really only a good buy if you're a tinkerer or happen to be lucky and get a really good unit.