Use only 2 screws for VESA mount

I bought a used aoc i2369vm, and when i checked the back of the screen, the top 2 vesa mount holes has no "screw holes" (i dont know the technical name of these), and i guess they fell inside the monitor. I found out later that these holes were just attached (glued) to the plastic support, not to the actual metal chassis.

So is it safe to just use the 2 bottom vesa holes? and whats wrong with AOC people!