2. The puck is stuck on software update
Connect an ethernet cable to the puck, unplug the power and plug it back in, wait 1 hour, switch on the puck and do the setup, go to Settings → Network → Status → Reset, connect to Wi-Fi, then remove the ethernet cable.
If the router is far from the TV: Unplug the HDMI cable from the puck, take the puck to the router, connect it with an ethernet cable, press the power button on the puck, plug in the power cable to the puck, hold the power button on the puck for 30 seconds, and leave it there with the power and ethernet plugged in for 1 hour.
3. The puck gets stuck on enter your PIN or enter your new PIN
Take out the power cable, put it back in, and leave the puck like this for 15 minutes.