Issues when changing the payload

Hello TTN-Forum,

i have encountered some issues while operating a Gateway in TheThingsNetwork and i cant get the reason why it behaves like that.

I have set up a Gateway in the, it connects fine and receives uplinks whenether it is supposed to have.

I also have an enddevice, a ESP32 microcontroller + rfm95 LoRa-Module, registered under the Applications. When adding the end device and sending the first payload from the controller to the gateway (raspi + LoRaWAN Concentrator ), it gets displayed correctly in the TTN-Overview live-data. But after changing the payload which gets send from the controller, the Gateway still receives a upload-link but the livedata displays no new data…

I can delete the end-device and set it up again, but it never works after changing the payload

Do you know the reason behind this behaviour?

Today i set my end device up again, but the Problem still exists… Is there no solution?

What do you mean with changing the payload? Are you reflashing the ESP at that time? Do you use OTAA or ABP?
When you say the gateway receives the data but it is not in the life data feed, where are you looking? TTN or gateway logs?

I am trying to implement a people counter. My Payload consists of 5 bytes, one has the value of the current people in the room. I can set my end device up and the payload gets received perfectly. If i change the value of the byte which represents the people (for example 6 instead of 5) then the issue appears.
I dont reflash the esp at any time. I use ABP.

This is the live data of the newly set up End device bevore changing the payload. I am looking at Applications->Live data
After changing the payload, nothing gets displayed here

This is the live data of the gateway. Gateways-> Live data
At all times it receives a uplink message, even when no data is shown at the application site

Looking at the second screenshot it seems you uplink counter is reset. The uplink counter needs to increase from the previous processed one to have the packet processed by the back-end. Lower values are considered a replay attack.
Are you sleeping the ESP between the transmissions? If so there are a lot of variables you need to keep save for the LoRaWAN stack to work within specification.

Hi and thank you for the reply,

where (in what variable) can you see the uplink counter? I couldn’t find much information about that.

My ESP is not sleeping between the transmissions, it is always online to display the current distance in my arduino sketch.

Uplink counter shows as FCnt in your screen shots. What is might be called in the software I don’t know (depends on what software you use).

Does the ESP reboot between transmissions? Because it clearly resets the (LoRaWAN stack internal) counter.