I am having the same problem with a pair of IP8M-2496 cameras.
After a bit of google-ing I see several people with different models of cameras with the same problem.
In my case one camera is looking out a window, so it blinds itself.
The other is outside but there is an object near by that is reflecting enough to blind that camera as well.
The commonality so far has been the V2.820 firmware.
I just down graded on of my cameras to V2.800 firmware.
That appears to be working.