We have just started installing 23 MV series cameras. On our first night vision test with an MV22X, we had such severe IR LED reflection on the inside of the dome that it rendered the camera non-functional.
To confirm, yes we removed the temporary protective plastic.
Usually this is due to smudging on the dome from the installers fingers. Have you tried taking a bottle of windex to the inside and outside of the dome, and then carefully replacing it without touching the dome? It could also be condensation on the inside, make sure the silica packet is still in place.
Kicking myself now because this article was hiding in plain site.
I think this was the problem in at least one of the cases earlier and suspect that I could improve IR quality by loosening some of the MV22x gaskets before tightening the covers back into place so they're pressed right up against the dome.