I have been making cables up on and off with success in the past. I have recently be trying and it aint just me, with problems.
I have 3 crimpers. The lastet being Quest TEL-6000.
I have 2 brands of cable and one brand of connectors.
Its seems a little random. One 11mtr was successful and a 15mtr from the same cable role failed.
The cable tester is a PEAK RJ45 AtlasIT cable analyser and that states the cable is straight thru. We also have a basic network cable tester which says they are straight thru.
I think one item that will be suggested is trying new connectors, but I will add then when a cable is failing we will recrimp it. 3 time on the one we're freaking at right now :)
Hope you can help.