I suspect that your install team is manhandling the cables, not realizing the consequences. This should not happen if the install team is certified in the OEM's system of cable installation. If you certified the channel that means its inclusive of patch cords on each end. if you take your cert machine and place it on the one of the offending channels what is the result? Here is an example of a well intentioned rookie Installer who thought this was permissible when installing the AP end of the cable into the cable well. This caused all sorts of issues from 100Mb connection to AP that would receive PoE but showed no signs of life. This is a Panduit CAT6A cable. Out of 40 APs installed the 12 this dude touched was hosed. Installing cables with a boot requires that you take your time and be carful not to tweak the cable or else the internal spline will help your conductors separate from the pins. I would recommend new patch cords WITHOUT boots and of the small diameter (28 gauge) variety. When installing remove the AP and carefully thread the patch through the mounting bracket taking care not to tweak the end. I would hold the body of the cable about 6 inches back and guide it into the well. It will in fact, be close quarters when installing the cable into the well. Your installer will have to be careful to not "abuse" the cable when pulling slack back to the mounting bracket https://www.panduit.com/en/products/copper-systems/patch-cords-accessories/patch-cords/utp28x7bu.html I don't have a cat6A at my desk but here is a sample of the Panduit CAT6 standard vs a CAT 6 small diameter. The size difference is easily seen and makes installs a little more forgiving in tight quarters.
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