Seems you node is really not connected to the server (“online” : false).
Please try to delete the node:
POST http://[your IP]:8080/v1/nodes/delete?access_token=[you access toke]&node_sn=[the serial number of the node, see last response]In the App logout your user. Change the custom IP address to the none SSL type (“http://[your IP]:8080”) and login again.
Try to register the node again.