Normal for hair thinning/loss behind the ears?

Ear pic is just before cleaning and blaming for accuracy.

Gunther is half Lab, half Basset. He’s always had sensitive ears which need a lot of TLC. He’s currently 2.5 years old and in his second year we’ve noticed a slow thinning of his hair under his ear and on the fold – is this a common Bassett thing?

We balm it as it gets dry, but the hair doesn’t seem to be growing back. Doesn’t seem to be causing any discomfort. Just odd.