apache24 ssl setup problems; "unknown protocol"

[Gary Aitken]

Hi all,

I'm trying to set up apache24 ssl for the first time; getting nowhere
very slowly.

Server starts up ok, serves port 80 normally as usual.
sockstat shows it listening on 443 ok.

When I attempt to connect I get this:

$ openssl s_client -connect 192.168.151.101:443
CONNECTED(00000003)
34379279064:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:/usr/src/secure/lib/libssl/../../../crypto/openssl/ssl/s23_clnt.c:782:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 7 bytes and written 291 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
SSL-Session:
     Protocol  : TLSv1.2
     Cipher    : 0000
     Session-ID:
     Session-ID-ctx:
     Master-Key:
     Key-Arg   : None
     PSK identity: None
     PSK identity hint: None
     SRP username: None
     Start Time: 1522531949
     Timeout   : 300 (sec)
     Verify return code: 0 (ok)

I assume the problem is the unknown protocol issue, but it's not clear
to me what the unknown protocol it's looking for is.
My extra/httpd-ssl.conf says:
   SSLProtocol all -SSLv3
and my extra/httpd-vhosts.conf does not override it.
The error log simply says:
    [core:debug] [pid 13758] protocol.c(1272): ... : request failed: malformed request line

Running apache24-2.4.25_1 on a 10.3 amd64

Thanks,

Gary