Gateway with sensors migrated from TTN V2 to V3; not found

I migrated a Raspberry Pi based ic880a Gateway with sensors from TTN V2 to TTS V3. after migration the two sensors couldn’t seen in Cayenne. I got the message that the GW is offline. I did a new install of the sensors and filled in correct credentials - without success.

Now, I deleted the device (Gateway) in Cayenne and am not able to add a new one with the same ID: conflict
I logged out and in again but it didn’t change: conflict
Even deleting the browser’s cache didn’t bring a solution.

Is the issue still there for the sensors?

After a few difficulties I was able to add the Gateway again and data are coming in. But now I‘m unable to change the icon from „Cayenne“ to „Gateway“. Error message: Could‘t be stored. Changing the name wasn‘t a problem.