Could be a dodgy connection or a wobbly bulb. Can LED's have a wobbly bulb? When my trailer lights stop working it's usually a wobbly bulb connection. I think LED 'bulbs' can actually stop working. Don't think it's a fuse for just one bulb. At least both lights would go out if it was a fuse, plus probably a few other things on the same fuse too. Most 'modern' things that 'last forever' still have the ability - just as well as old things did - to stop working.
I have a Clairol hairdryer that I bought in 1974 that still works. Apart from this and a Sinclair calculator (decided not to bother with a C5) pretty much everything else I purchased in the 1970s has now stopped working though. I had a black marker pen that worked until recently that was my fathers, and he died in 1990.
Perhaps somebody can be more helpful than I am and tell you how to check and/or change the bulb.
