Devices Won't Connect

I have multiple sensors from Dragino and Seeed. I had them setup in the Helium Chirpstack console and everything was working fine. I had each device setup in a single application when it was working. However, I then wanted to create multiple applications so each sensor could send their data separately with a webhook. So I deleted all the extra devices and created new applications and re-added the devices. Now, only 2 of the 6 devices have re connected and I can’t seem to get the other 4 devices to connect.

What should I do to try to get them to work?

When you deleted them, you also deleted their device session keys. The devices themselves do not know they have been deleted from the server, so when you re-add them they are still broadcasting with their original keys. You need to force them to send another join-request. How you do this depends on the device but for the vast majority power cycling them will do it.