Some thing you can try:
- Press the button for more than 10s
- Don't open more than 1 tab with phoson
For me your problem can come from
- A communication problem, (you are using rapsbee ?) Don't use metal case, try to disable wifi and bluetooth from raspberry to test.
- A configuration problem, on phoscon you have the last deconz version and last firmware version too ? Nothing strange on config page, something like that (this screenshot is not up to date)
If you havent device at all, you can try to reset the gateway.
- An hardware problem on your raspbee. You haven't another devices to try ?
Even in deconz with the graphical UI, you can see only the raspbee ? no more nodes ?