Not sure what and how you are testing. Any additional information is lacking.
If you want useful feedback from others, you should provide good and detailed information yourself first. To prevent others having to guess for it and prevent unnecessary speculations.
What I observe in above screenshot is that the node appears to make join requests like crazy which is abnormal.
First the node appears to make join requests every 6 seconds, then later the node appears to be manually reset every few seconds. Both are not normal.
What sketch is used? Which LoRaWAN library is used (I assume the one integrated in the CubeCell Arduino Core)? What version of the core are you using?
A standard unmodified sketch like the ‘LoRaWAN’ example or a modified example/custom sketch? Do you only use the TTIG or are other gateways also in range of the node? What is the distance between node and TTIG?
Have you tested another node with the TTIG (preferably a different type)?
Join accepts that are being missed by a node are often caused by timing issues on the node.
Give the node some time and leave it joining for 10 to 20 minutes and observe what happens in the console application data and the console gateway traffic. Also check the times between each subsequent join request and the spreading factor of each join request and a possible join accept.
The node seems to retry a failed join request every 6 seconds which is very uncommon.
This could be caused by ill-behaving code (sketch) running on the node or a problem in the LoRaWAN library.
According to the LoRaWAN Regional Specifications:
JOIN_ACCEPT_DELAY2 is 6 seconds.
JOIN_ACCEPT_DELAY1 is 5 seconds.
I’m not sure if latter means exactly 5 seconds or max 5 seconds but max seems most plausable.
In case of max 5 seconds, a 4 seconds delay is valid and in case of exactly 5 seconds, 4 seconds will be too short.