Looking for recommendations for a constant diaper rash that will not go away.

My 14 month old constantly has a diaper rash. IT WILL NOT GO AWAY. We have tried everything! We’ve tried air drying, all kinds of creams/ointments, upped his diaper size, changed wipe brands, changed him right away and even prescription creams. Nothing works.

The rash will move from his butthole to his little balls and back and forth.

Give me ANY AND ALL RECOMMENDATIONS PLEASE!!!!