GMMK numpad error in SignalRGB

My numpad was flashed to QMK firmware. Now signal picks it up but I get this error in console (so it wont control the numpad RGB):

Error - Error: device.write(): HID handle is invalid, confirm that the protocol type selected is HID.
StreamLightingData():358
sendColors():348
Render():97

I tried dropping the GMMK_Numpad_QMK js file into my plugins directory as instructed by the troubleshooting doc but its still throwing that error. It also shows as a generic device in signal even though it shows GMMK Numpad for the name.
gmmk numpad detail