Medial midfoot heel pain, significantly with extended bodyweight bearing, may be because of tarsal tunnel syndrome, that's because of compression in the posterior tibial nerve. Sinus tarsi syndrome manifests as lateral midfoot heel pain and a feeling of instability, specifically with improved exercise or going for walks on uneven surfaces. https://www.theorthopaedicandpainpractice.com/a-comprehensive-guide-to-treating-foot-heel-pain/