I’ve noticed lately on longer rides that I tend to get a hotspot on the bottom of my left heel. This is usually after 3-4 hours, but sometimes sooner if it’s hot out. This has happened with Swiftwick and Darn Tough socks. The bottom of my heel will feel a little raw after these rides almost like a blister would form eventually. I never had this before the last few months 
This has happened a few times in my road shoes (Lake 239 with custom insoles) but more frequently in SPD shoes (Specialized Recon 3.0 with G8 insoles). The Recon overall seem to fit well and help my wonky right knee track better.
I don’t know if it’s a shoe issue because my shoes otherwise feel pretty comfortable. I googled a bit to see if people have have had this issue and most comments were about ankle/heel pain on the sides like if the opening of the shoe doesn’t work well for someone.
I’m stuck so figured I’d ask if anyone else ran into this and if anything worked. Thanks!