Janus not sending proxy authorization header

Helo,
I am using janus version 1104 (1.1.4) and sending registration and sip invite to kamailio server. Both janus and kamailio is in same LAN. When I make a call from janus to kamailio, kamailio does authentication challenge saying proxy authentication required, Janus just ACK and stops there without sending reinvite with authorization headers. Kindly advice what to do in this case
sip client -------->[janus public ip] [janus private interface]-------------> [ kamailio private ip].
if this is the version issue , kindy suggest how can i downgrade janus version and which is the stable one ?