have you checked/swapped any of the Patch cables in the questionable run?
Just another thing to check ( maybe you have)
I've had a couple bad new patch cables once in a Blue Moon back in my cable pulling days.
I would really like the clean look of the patch panels and keystone jacks, But when I run to the edge of the
cat5e 100Meter limit, I try to avoid patch panels and keystones and go straight from Cam to POE switch. (homerun) I won't win any beauty contests in my Rack, but it works.
( I know it doesnt follow low voltage code) but I'm not running Cardiac data through a hospital network anymore, so fk it.....
It's not pretty, but I eliminate a lot of components to troubleshoot. My building is shaped like a Y and the Rack is almost in the middle of the Y. footage for the PTZ ( 802.3at) camera is about 200 ft. I have 2 runs that are 238-240 feet. running a 5241 z12 and a 5442 As LED.
I only had to re-terminate 1 end, (had my blue/white and green/white crossed
)