Brake sensor stuck on

I just replaced my junk Chinese mechanical brakes with Shimano hydraulic brakes for my ebike.

Problem I'm dealing with is that the 2 pin brake sensor cable for the front brake seems to send a signal that it is permanentely on. The brake lever isn't compressed, the rear brake sensor is working fine and the only part of the wiring which has changed is from the 2 pin to the new brake lever.

I know it thinks it's on because the brake light stays on unless I disconnect the front brake sensor cable.

Does anyone know what the issue could be?