I finally found that adding
SSL_set_tlsext_host_name(ssl,hostName);
f.e.
SSL_set_tlsext_host_name(ssl,"www.morphos-storage.net");

makes it work, without even setting a cb

why this is the only one site I found to need that, I don't know.

[ Edited by alfie 01.07.2024 - 19:13 ]