@joseph_1979

I have a similar problem.
Bought 6x CX820 in July.
One, often works well, but often drops a gazillion packets and is unusable.
Often, the issue starts at night when it's dark.

Tested the Ethernet cable with a RJ45 tester, and it looks OK.
I am trying a different port on the PoE switch at the moment, and the jury is still out.
The PoE switch is not power maxed-out, by the way.
What is interesting is that it does NOT happen all the time.
This makes me think more software bug.
On the other hand, the other cameras don't seem to have a problem? Very weird.