tap handle

Isolating a central heating boiler but the gas is already off. If you were a betting person, is this tap off or on? It rotates 90 degrees.

I have a monobloc mixer tap with 2 levers. The cold tap will no longer grip the cartridge (20 teeth). Tried the hot lever on cold side and worked fine so definitely an issue with tap lever not gripping the cartridge teeth. Does anyone have any advice on how to get it to grip? I had thought I...