In 2.1~rc20, upstream rewrote most of the PUSH_REPLY handling ("Optimized PUSH_REQUEST handshake sequence to shave several seconds off of a typical client connection initiation"), maybe now there is a corner case where no reply would be sent (at all) if no push option is specified, making client hang unless a dummy push is configured on the server.
Could you attach the client and server logs in both cases (success/failure) ?
In 2.1~rc20, upstream rewrote most of the PUSH_REPLY handling ("Optimized PUSH_REQUEST handshake sequence to shave several seconds off of a typical client connection initiation"), maybe now there is a corner case where no reply would be sent (at all) if no push option is specified, making client hang unless a dummy push is configured on the server.
Could you attach the client and server logs in both cases (success/failure) ?