Cant connect to Puck after some time (cant find it via scan)

As I understand it, Bluetooth Low Energy connections have to have packets sent from one device to the other at regular intervals. For Puck.js it's a minimum of 50 times a second.

If a few of those don't get through for whatever reason, the connection is considered to have disconnected and both devices disconnect.

To figure it out you can just hook onto the connect and disconnect events.

Once you have a connection, upload the following:

NRF.on('connect',()=>LED1.set());
NRF.on('disconnect',()=>LED1.reset());

Now the red LED will light when the Puck is connected and will go out when it's disconnected.

I guess the other possibility is you're managing to upload some code that completely locks the Puck up? Perhaps if you find code that always makes it disconnect then you could paste it up and I'll try and see what's wrong.

Also, I'd make sure you're on the latest firmware (1v89 at the moment). I know that 1v88 that it shipped with did have an issue where if you called updateServices with the wrong arguments it's cause an assertion which would reboot the device.