Of my four birds, the only dyad that is a little bit troubled is between my female budgie (Winter) and my male cockatiel.

Mostly what I notice is they want a good amount of space between them. If one of them wants to get into or out of the cage and the other is in the doorway, there is posturing and beak banging, until one of them backs off.

That's OK. I'd expect them to have a flock bond with each other whether they like each other or not. It's all right for birds to scuffle with each other a little as long as there's no serious violence.