https://support.sectigo.com/articles/Knowledge/Sectigo-Intermediate-Certificates?retURL=%2Fapex%2FCom_KnowledgeWeb2Casepagesectigo&popup=false
Good luck.
Cheers,
Scott.
Note: Few legacy systems, that no longer receive any updates from their vendor, may not trust our SHA-2 Certificates. To enable them to trust our SHA-2 Certificates, we recommend our customers to include the Cross Signed Certificate into the Server Certificate chain. This will enable those legacy systems to trust our SHA-2 Certificates.
Good luck.
Cheers,
Scott.