The problem was with the mtu size of docker interface. I have a PPPoE connection which has less then 1500 bytes mtu size - so what I had to do is to set MSS clamping in iptables.
iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
More info about the solution can be found here: ssl - OpenSSL hangs at CONNECTED(00000003) - Stack Overflow