I little older thread, but thought I’d throw in my $.02. I’m currently in flight, 330-900neo, Comfort+. I’m using a power adapter that came with my M2 MacBook Air. It has two USB-C ports on the bottom of the plug. I plugged this in, upside down, so the cables came out out towards the top, and got the red light when plugged into an iPhone and an iPad Pro 11” (at the same time).

Unplugged adapter, removed iPad, and plugged it in so the cables were at the bottom. Got the green light and plugged in iPhone. All good. Then plugged in iPad. All still good.

HTH