ngx_stream_log_module log_format not working

[CCS]

This worked for me without and issue. Try and copy. 

log_format proxy  '$remote_addr [$time_local]'
                         'with SSL Server name "$ssl_server_name" '
                         'proxying to "$selected_upstream" '
                         '$protocol $status $bytes_sent $bytes_received '
                         '$session_time';

access_log /var/log/nginx/nginx-access.log proxy;

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,283403,283414#msg-283414