bleepingcomputer[.]com/news/security/microsoft-defender-wrongly-flags-digicert-certs-as-trojan-win32-cerdigentadha/
This should actually be fixed now, but several sites are reporting the bug as ongoing. If you do get the false alerts, make sure Defender is updated to 1.449.431.0 or newer.
Microsoft has reportedly fixed the detections in Security Intelligence update version 1.449.430.0, and the most recent update is now 1.449.431.0.