Battery Power bank with picade

Hi,
I have some issues with the picade when powered by a power bank (5v 3A output).
First time I tried it worked like a charm. Then it sometimes power up, sometimes not. I have the feeling that the power bank check if there is something on the other end and if not do not send the juice.
Then sometimes there is maybe resident power and it works and sometime no.
That power bank has a screen that show whether something is draining the battery or not (showed as output).
When it works : when I press the picade power button, the battery screen changes to show that there is an output and the picade start up
When it does not work: when I press the picade power button, nothing happen and the power bank screen does not change and the power bank go to sleep.

Is there anything I can do to make it work. Can we add an option that the picade start as soon as there is power: so basically the power button is only use for switching off, not starting up ?

Thanks

Edit: and what is the button labeled “switch” on the picade X HAT ?