@madler Are you bringing the PowerBank power into the USB-C connector on the board? Then maybe the power bank cannot detect the LilyGO board, due
to small current consumed. This is a common problem with power banks!
Or the 2 pin battery connector? Possibly GPIO 35 must be enabled for battery.
You could raise an Issue here:
https://github.com/Xinyuan-LilyGO/LilyGo-LoRa-Series/issues
-Terry