certificate issue for "DigiCert high assurance EV Root CA" and can't access my Citrix account remotely

I am a medical provider and need remote access to the electronic health record from home using my personal laptop. this is supposed to be easy by logging into my.ardenthealth.com and accessing the program that way. I am able to login in to the first level but at the second level to actually let me into the program, I get the message "You have not chosen to trust "DigiCert High Assurance EV Root CA", the issuer of the server's security certificate. contact your help desk for assistance.

I have spent many hours on the phone with my work IT desk trying to figure this out with NO PROGRESS. They ultimately said it is a MAC issue so contact apple., So here I am. please help.

I indeed DO have this certificate in my keychain and it is accepted to trust so this is simply not true. What do I do now?