Brake light issue-help needed

[Batfink]

being a bank of LED they all come on with general lights, using the brake levers makes them brighter, not turn on more.

if your horn works then the issue is between your fuse (#5) and your switches.. both front and rear lever supply power to lights via same wire (white with black stripe).
so if horn has power and you have 2 wires into light assembly that is 1 constant when ignition is on (headlights are on) and the other is on/off according to if a brake lever is activated then it's a problem in the rear light assembly.
I think shifu was trying to say even the OEM lights are cheap chinese crap LOL