I set up a simple web server using: openssl s_server -key privkey.pem -cert fullchain.pem -accept 443 -www -msg When subversion from 15.5 connects I get: ACCEPT <<< ??? [length 0005] 16 03 01 02 00 <<< TLS 1.3, Handshake [length 0200], ClientHello ... When subversion from 15.6 connects I get: ACCEPT <<< ??? [length 0005] 01 00 01 fc 03 139678608217920:error:1408F10B:SSL routines:ssl3_get_record:wrong version number:ssl/record/ssl3_record.c:332: <<< ??? [length 0005] 01 00 01 fc 03 139678608217920:error:1408F10B:SSL routines:ssl3_get_record:wrong version number:ssl/record/ssl3_record.c:332: <<< ??? [length 0005] 01 00 01 fc 03 139678608217920:error:1408F10B:SSL routines:ssl3_get_record:wrong version number:ssl/record/ssl3_record.c:332: