Nearside (passenger) rear brake light keeps going out and the dash warning symbol keeps popping on. Rear-screen and offside(drivers side) all work fine.

if I replace the bulb with a brand new on or switch it out with an existing one it doesn't work at all but if I put the current one in it works for like 2-3 times of brake presses then doesn't and the dash warning light comes on again. It's bugging me.. I've tried cleaning the bulb connector and blowing into the bulb socket area incase of any dirt.

any ideas? Seems bizarre that only that 1 bulb works. Its really annoying having an inconsistent bulb issue. Anyone had similar problems?
cheers