XX52A. Black picture

[Maltby]

I recently took down my Legacy Airsight  cameras and replaced them with XX52A.  After installation the worked fine but then one of them, although it connects just fine and the says it’s online, the picture is black.  Sometimes a picture will show up but more often than not I get a black screen.

I have uninstalled and reinstalled several times but it has not cured the problem.