Thanks for posting and welcome to the Bose Community. I am sorry to see that your headphones power themselves off and would love to look into this further for you.
Firstly, I would recommend that you perform a reset on the headphones by:
Power off your product, then wait 30 seconds
Connect your product to a wall outlet using a USB charger, then wait five seconds
Disconnect the USB cable from the headset, then wait one minute
Power on your product.
I would also recommend that you plug the headphones into a different power outlet and allow them to charge for a few hours despite the LED information that the headphones give. Please also check inside your Bose Connect App if possible to ensure that you have no Auto-Off settings enabled. This will be under settings > Auto-Off.
I look forward to hearing back from you about the result of these steps. If any other users are having a similar issue after performing this update please do let us know.