The OCSP verification specs began failing recently as a result of Let's Encrypt no longer supporting OCSP. The Atlas certs thus no longer include OCSP endpoints, which breaks an assumption in the specs.
If we want to keep that test (which I think has value, as it confirms that the OCSP verifier is able to extract OCSP endpoints from the cert), we need to use a bespoke cert, rather than expecting the Atlas certs to include those endpoints.
See https://github.com/mongodb/specifications/tree/master/source/ocsp-support/tests#mock-ocsp-responder-testing-suite – which indicates where we can find appropriate certificates to use for the OCSP tests.