Only happens in one shoe in one pair I own, (on the side of the foot below big toe). No obvious defects or lumps in the shoe and different socks don't make a difference.
Any suggestions of modifications I can do to the shoe, or is it a case of applying a bit of tape each run in this pair?
But yeah some tape can work. I just use micropore tape and that holds up surprisingly well, but vaseline is always the first option, and avoid socks with distinct seams.