Yes, that's why I set "SSLStrictSNIVHostCheck On" -> according to the
documentation "If set to on in the default name-based virtual host,
clients that are SNI unaware will not be allowed to access any virtual
host".
I set it in the default virtual host and in my "second.server" (that is
supposed to be TLS 1.3 only) but it didn't change the behaviour (i.e.
second.server still accepts TLS 1.2 requests...)
TLS revision describes the handshake protocol. Either the listener accepts
TLS 1.2 handshakes, or it does not, it won't look at SNI until the handshake
is in flight with the respective TLS handshake.
This points out the possibility of multi-homing the box with one IP which
accepts TLS 1.2+ and a different IP listening with TLS 1.3 only.