@ncollins Great! Seem the problem is the delay. With 1 ms or 100 ms I have double message, but with 200 ms I only one message. Thanks a lot.

I have a problem with lost message when openhab change two relay at the same time.
The relay are on the same node (arduino Pro Mini with nRF24L01+) and openhab is connect via WiFi Gateway using ESP32.
I am investigate to see if the problem is a buffer messages because the node receive multiple message (for the same child/relay).
In effect seem that mysensors binding on openhab duble the message:

2021-03-14 18:57:02.898 [ome.event.ItemCommandEvent] - Item 'LuceEsternaAia_Status' received command OFF

2021-03-14 18:57:02.903 [nt.ItemStatePredictedEvent] - LuceEsternaAia_Status predicted to become OFF

==> /var/log/openhab2/openhab.log <==

2021-03-14 18:57:02.954 [DEBUG] [ensors.handler.MySensorsThingHandler] - Adapter: class org.openhab.binding.mysensors.converter.MySensorsOnOffTypeConverter loaded

2021-03-14 18:57:02.965 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Node 3 found in gateway

2021-03-14 18:57:02.969 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Child 3 found in node 3

2021-03-14 18:57:02.974 [DEBUG] [rsAbstractConnection$MySensorsWriter] - Sending to MySensors: 3;3;1;1;2;0

==> /var/log/openhab2/events.log <==

2021-03-14 18:57:03.027 [vent.ItemStateChangedEvent] - LuceEsternaAia_Status changed from ON to OFF

==> /var/log/openhab2/openhab.log <==

2021-03-14 18:57:03.081 [DEBUG] [rsAbstractConnection$MySensorsWriter] - Sending to MySensors: 3;3;1;1;2;0

2021-03-14 18:57:03.140 [DEBUG] [rsAbstractConnection$MySensorsReader] - Message from gateway received: 3;3;1;1;2;0

2021-03-14 18:57:03.146 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Node 3 found in gateway

2021-03-14 18:57:03.149 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Child 3 found in node 3

2021-03-14 18:57:03.151 [DEBUG] [ensors.handler.MySensorsThingHandler] - Updating channel: status(V_STATUS) value to: OFF

2021-03-14 18:57:03.159 [DEBUG] [ensors.handler.MySensorsThingHandler] - Setting last update for node/child 3/3 to 2021-03-14T18:57:03.000+0100

2021-03-14 18:57:03.172 [DEBUG] [rsAbstractConnection$MySensorsReader] - Message from gateway received: 3;3;1;1;2;0

2021-03-14 18:57:03.174 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Node 3 found in gateway

2021-03-14 18:57:03.176 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Child 3 found in node 3

2021-03-14 18:57:03.179 [DEBUG] [ensors.handler.MySensorsThingHandler] - Updating channel: status(V_STATUS) value to: OFF

2021-03-14 18:57:03.184 [INFO ] [rsAbstractConnection$MySensorsWriter] - ACK received for message: 3;3;1;1;2;0

2021-03-14 18:57:03.187 [DEBUG] [ensors.handler.MySensorsThingHandler] - Setting last update for node/child 3/3 to 2021-03-14T18:57:03.000+0100

It's correct ?
If yes, on the node I can use:

#define MY_RX_MESSAGE_BUFFER_FEATURE
#define MY_RX_MESSAGE_BUFFER_SIZE (6)

but on ESP32 gateway what I can do?

Thanks in advance for the help.

Massimo