New quad works when plugged into beta flight but not when unplugged

Just done my first full build. All seems to work on the bench when beta flight is plugged in, and also initially when the lead is pulled from the FC, control through taranis all correct. But when power is cycled I get no control at all, XSR is still bound.
Any idea please.
Omnibus f4 pro.
Emax RS2205
Littlebee 30A.
Many thanks.

Do you get any LED’s :rotating_light: when it is unplugged from USB?

Also could you share a photo of how everything is wired together as maybe the battery is not connected to the correct location?