Princessa... Wiggle the center posts my dear. Can't really get to them in the atty, but you should be able to wiggle the one in your RIVA battery, and raise it up a hair. Then it should make contact with the atty fine.
I notice this issue mostly with ego style attys, and cartos in general. But, it's an easy fix. Leaford has a video about it from way back about the V4L shorty batteries not making connection.
Will definitely try that! Will wanna watch the vid, of course... if something can break, I'm gonna find a way LoL
And the ego t bats, are on the long side. Especially when paired with matching atties and carts. I too really like the 900mah ego size. Even the 6/750's for something pocketable. They all have their place. And they are all within [bold]arms reach[/bold]
now, that depends on the length of the arms