assuming there is no pain associated with this, and speaking as a completely unqualified non-professional doofus, this looks like eversion.
https://thumbor.kenhub.com/Rtmxrl7nbbu9yn4PxKN1IfLa8q4=/fit-in/800x800/filters:fill(FFFFFF,true):watermark(/images/logo_url.png,-10,-10,0):format(jpeg)/images/anatomy_term/eversion-of-foot/JJFVZM3waanu7bd2V5GCmg_Eversion_of_foot.png
you can find a load of stuff on the web to help you counter this. you should be aware that any solution will take time and may involve several different types of exercises and modalities. if you don't already do weights, then good lifts for lower leg stability would be deadlift, cleans and squats, deep squats. avoid machines if possible and concentrate on low weight with good form.
also, get a broom handle, a relay baton, or similar, and roll your foot over it, along the full length of the sole, front to back, and back to front. build up SLOWLY to doing this ten times per foot twice per day.
one good thing I have found for a variety of form-correction issues is to get the athlete on a treadmill where they focus entirely on the particular aspect of form or gait they want to correct. run around 1 mile to warm up, then jog at a pace around half-marathon pace and concentrate just on landing your foot with the toes pointing forwards. start with a fairly short distance and as the muscles and tendons adjust gradually increase the distance. you can try doing intervals at this (on a treadmill), run 400m while concentrating hard on foot placement, then relax for 400m, then concentrate on foot placement for a lap and so on. do this once per week alongside other therapies. I have had good success like this with arm carriage, knee alignment, hip displacement and iliotibial band issues. should work for eversion, too.
Cheers.