I have found an interesting behavior of the SSL Server Test, which might qualify as a bug.
I am running an virtual host configuration with default host domaina.example and another virtual host www.domainb.example. Since there is (by accident, forgot to define an alias) no defined virtual host for domainb.example (without www subdomain), requests to this domain are served by the default host. The certicate used for the default host is not valid for domainb.example, so requests to domainb.example fail due to a certificate mismatch.
Running a test on www.domainb.example works fine for the first time, giving me a notice, that this host is only reachable when using SNI. Expected and perfectly fine, except that the headline saying "SSL Report: domainb.example" while it shoud say "SSL Report: www.domainb.example" because this is the host that was tested. One might think, this is just a minor problem, but when I want to run the test again, the real problem begins. The link "Clear cache" also lacks the www subdomain, and instead of re-testing www.domainb.example now the host domainb.example gets tested, causing a certifcate mismatch error due to the accidential misconfiguration. When I saw this the first time, I was really confused, because I did not change anything in the virtual host configuration between the tests. It took me a while, to figure out, the www was accidentially stripped between the tests. Without the mismatch, I even would not have noticed, that another host was tested.
It would be nice, if the "Clear cache" link would behave as expected, testing the same host as before.