Error 515 No Device Connected Bluetooth

Hello, I'm asking for help because I have a problem.
My application consists for the moment in 2 pages, a first one of welcome where we connect the app to an Arduino board in bluetooth via a bluetooth module (and in the future directly to the board), and then a second one with buttons supposed to send a letter and in return the arduino code launches its instructions at the reception of the said letter.
You can't go to page 2 until the bluetooth device is connected, and yet when I press my button on page 2, I get a 515 "Not Device Connected" error.
I don't understand why I'm getting this error and I'm asking you for help.
Many thanks in advance

Screen 1 Blocks

Screen 2 Blocks

Arduino Code


the bluetooth connection doesn't work across screens. You can use virtual screens to maintain your connection across “views”.

An example:

Thanks ! It's good i have apply a bluetooth for all screen.