Does a CAT cable contain uplink and downlink wires?

Hi!

I upgraded to 250/250 Mbps internet. I get a stable 240 Mbps down but my uplink never goes over 100 Mbps.

I just got off the phone with the ISP service technician and they say I must buy a new cable to test as they can verify my speed cap with them is set to 250/250 Mbps. I've never experienced any problems before. I was even maxing out the upload to my NAS (HDD not SSD)

Question is: Could it be that the cable contains wires for uplink that have been damaged? Cable must be 10 yrs and might have been run over by a chair sometimes during these years.