RAK7201 WisNode Button 4K - ERROR 99

Hi,

I am trying to configure a new RAK7201 WisNode Button 4K device that I would like to use with the Helium network. I have added the device to the Helium Network and I have set the dev-eui, the app-eui and the app-key. I am following the instruction shown here: https://docs.rakwireless.com/Product-Categories/WisNode/RAK7201/Quickstart/#connecting-to-helium-the-people-s-network.

Now, I get the ERROR99 at the at+join command

at+version

OK V1.0.2.210520_Release

at+get_config=device:status

OK Board Core:RAK4270
MCU:STM32L071KB
LoRa chip:SX1262
Heartbeat interval time : 0 h
Button1 Port£∫1 Information: A
Button2 Port£∫1 Information: B
Button3 Port£∫1 Information: C
Button4 Port£∫1 Information: D

at+get_config=lora:status

OK Work Mode: LoRaWAN
Region: EU868
MulticastEnable: false
DutycycleEnable: false
Send_repeat_cnt: 0
Join_mode: OTAA
DevEui: XXXXXX HIDDEN XXXXXXXX
AppEui: XXXXXX HIDDEN XXXXXXXX
AppKey: XXXXXX HIDDEN XXXXXXXXXXXXXXXX
Class: A
Joined Network:false
IsConfirm: confirm
AdrEnable: true
EnableRepeaterSupport: false
RX2_CHANNEL_FREQUENCY: 869525000, RX2_CHANNEL_DR:0
RX_WINDOW_DURATION: 3000ms
RECEIVE_DELAY_1: 1000ms
RECEIVE_DELAY_2: 2000ms
JOIN_ACCEPT_DELAY_1: 5000ms
JOIN_ACCEPT_DELAY_2: 6000ms
Current Datarate: 5
Primeval Datarate: 5
ChannelsTxPower: 0
UpLinkCounter: 0
DownLinkCounter: 0

at+join

ERROR: 99

Why is the device not joining the network?

OK, after several attempts I managed to have the device joining the network.