On one client, the speed is 100Mbps, on the other 1000. Why?

Question

Computer networks

Good time of the day. We have a mikrotik 1100 x2 router, a switch, a patch panel and a fleet of ~50 machines. From the patch panel, respectively, the lines diverge into the cabinets. In one of the offices, three people are sitting on one outlet through a small lousy switchboard. And here's the problem: at one workplace, the speed is 1 Gbps, at two neighboring 100 Mbps. What could be the reason? Is it possible to raise the speed of two neighbors to gigabit? If the question is stupid, I apologize.

Answer 1

that only 2 pairs of 4 are crimped?