Hello @Danny Chrismas ,
Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.
If the TXT value is correctly configured and the validation state is still pending for more than 24 hours, the internal process for the support team is to reach out to DigiCert for further assistance on the domain validation. So, if you have a support plan, I request you file a support ticket, else please do let us know, we will try and help you get a one-time free technical support.
Thanks,
Gita