I don't think that's all that happened.
The server certs we're having issues with are GlobalSign and DigiCert, not Sectigo, and the problems are intermittent.
The client OS in question has updated certs and is on OpenSSL 1.1.1.
I manually removed the AddTrust certs but that didn't help either.
Regards,
-scott
Welcome to Rivendell, Mr. Anderson.