I think it's always been a thing. I tend to walk out of or pop the heel of my left foot when walking in non-containing shoes. When I got measured for workout shoes they're like hey your left foot is a size smaller than your right. I'm like oh, so that's why I walk out of that shoe.
But now the problem is I have two pairs of just classic heels I'm trying out. I've needed just a nice pair of businessy type black heels forever. I usually give up and return the ones I try, but I'm determined this time because I need close toed heeled dress shoes. The first pair are a little taller heel, which I like, but the right foot is fairly tight. I walk out of the left one. I think once broken in, the right shoe would be fine.
Second pair is lower heel, right foot is comfy, and at home I thought the left was good. Today I'm wearing them for the first time and I walk out of the left. So now I'm like why bother going with the lower heel that I like less if I'm still going to have the same problem. Now to see if blow drying the right shoe will stretch it enough and adding an insole to the left makes it tighter on the other pair.