FS-3688 d'oh missed one line of the patch.... This should be the keeper

src/mod/endpoints/mod_sofia/sofia.c

@@ -5794,6 +5794,7 @@ static void sofia_handle_sip_i_state(switch_core_session_t *session, int status,
 							if (sofia_glue_tech_proxy_remote_addr(tech_pvt, r_sdp) == SWITCH_STATUS_SUCCESS) {
 								nua_respond(tech_pvt->nh, SIP_200_OK, TAG_END());
 								switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "Audio params changed, NOT proxying re-invite.\n");
+								switch_core_session_rwunlock(other_session);
 								goto done;
 							}
 						}