That is indeed a peculiar issue. Can you verify what kind of certificate you are using? self-signed, third party, domain? It would seem that Vision cannot establish a secure connection to the search service location when Vision is accessed through anything other than localhost (and since you cannot connect to this, your databases cannot be indexed and you cannot search in Vision), and I'm wondering if that has do with the certificate. What appears under the Subject Alternative Names (SAN) in the certificate?
Are Vision and Web API installed and running on the same machine?
Are you using any aliases for the Vision machine or Web API machine (if Web API is not on the same machine as Vision)?
Would you be able to share what the "maintenance" was?