Oil light on dash stays on until engine is started

Honestly can't recall the old behaviour, but after an oil change, when I start the car, first ignition click the oil light comes on and stays on, solid yellow. Turns off once the engine is running.

I've checked the oil levels, dipstick, etc - should have plenty of engine oil, so honestly not sure if this is normal and o never noticed before, or if I have a problem somewhere!

sounds like its working, sound light up when no pressure, ie engine not running and extinguish and stay off as soon as engine starts