Hi Dennis,
I suspect this is related to the topic – Upcoming change: valid authz reuse
Once a domain has been validated, that authorisation is remembered for a period of time ( 90 days currently I believe), so requesting via a different type of challenge ( http in your case) will result in always getting a “pending” unless the script takes notice of the “status”:“valid”. I’d suggest opening this as an issue on the dehydrated site. It should recognise the valid status, and simply obtain a new certificate.