As part of the external_auth.yml suite, the test "ldap_mongos_health_checking_crash.js" enables a firewall between the mongos and the ldap server. This firewall is only enabled on linux. If this test runs concurrently with tests that require being able to talk to the LDAP server, those tests will fail. As part of SERVER-64322, concurrency in the external_auth.yml test suite was disabled. We would like to eventually enable it again. When that happens, there will be failures and this issue will need to be addressed.