See also:
[Resolved] Omega 2+, Powered without Dock, Shuts off after 18s
[Resolved] Onion Omega 2 + booting problem
and the the power supply related posts of @ccs-hello

At least try to put a 10uF (or more) "curative" capacitor directly between the 3.3V and GND pins of Omega2+ ;-)

Or even have a read through Powering the Omega with No Dock