The worst thing I see is guys not knowing about the bend ratio on any of this data wire.

Take a piece of Cat 7 and have it make a really tight turn coming out of a top, or bottom, plate and you can reduce it to a nice low speed wire run since you have completely changed the relationship between the pairs. May as well tie a few knots in the wire.....

Cat5e can do gigabit up to 328’. That is the spec.
If your not getting that at the switch or after it, i would suspect there is a bad cable.
You should use a tester for this.
I saw something like this last year. After looking at all of the obvious things first i tested the line and it came back with broken pairs in the cable and no easy way to fix it.