Regular ethernet RJ45 cable on a network port wouldn't negotiate 2.5G speed with the AP directly attached. Instead the UI displays 0.1G

In this example port mge-0/0/13 shows 0.1G speed instead of 2.5G:

There was a layer 1 issue. The port started negotiating properly and working fine now after the Ethernet cable was reterminated. 

2025-01-22 : Article Created
2026-06-09 : Made the article public.