Aquaphor likely used as a barrier ointment or protectant.
If wrapping, the feet need to stay dry, so keeping him on clean dry bedding may help or at least change wrappings daily.
Contact Dermatitis is a suggestion - something you can take and run with to figure out whether or not that's what...
Contact Dermatitis. Feet need to stay dry if wrapped.
https://www.backyardchickens.com/articles/early-stages-of-contact-dermatitis-foot-pad-dermatitis.78413/