I have a heal spur, which is basically arthritis on the heal and feels just like PF. Mine hurts more in flat shoes, particularly wellies or (surprisingly) trainers. I work on a farm and do a lot of walking I blame years of wearing wellies and muckers. I also walk very heavily on my heels, which won’t have helped. I find wearing good walking boots with insoles helps, and insoles in wellies in winter. Strangely the heals I wear for work don’t affect it at all.