There have been recent known issues with millions of revoked SSL certs by Apple, Google, Godaddy and others. Just FYI - prob not your specific issue, but would do a quick check nonetheless to be sure.
"Mass Revocation: Millions of certificates revoked by Apple, Google & GoDaddy" [March 13th, 2019]
Read more at: https://www.thesslstore.com/blog/mass-revocation-millions-of-certificates-revoked-by-apple-google-godaddy/