Node does not re-connect to the GW after loss of contact

[bgunnarb]

I have built a handful of nodes that talk to two MQTT GW in different locations. One GW is based on an ESP8266, the other on an Arduino UNO with a W5100. I have found that two nodes, that are placed fairly far away from the GW, now and then loose contact over the RF. That could be due to bad radio conditions or a power outage on the GW. The problem is that after that, the node does not re-attach when conditions improve.

This does not happen to nodes placed closer to the GW. Is there any way that the node can be made aware of that it has lost contact and then enter presentation mode again? Could the 'ack' be used for that?

I am using MySensors 2.1.1