From your description, it sounds like you were fulfilling your role fine, though it's possible you're doing something incorrectly without realizing it's a problem. Either way, assuming they kicked you for gameplay reasons, they should have at least mentioned what they thought you were doing wrong. If it's something as simple as overpulling, a quick "slow down" would have probably solved the issue. Just suddenly kicking you seems unnecessarily harsh.

It could be because you boosted, but I doubt it. I don't see any trend of kicking boosters if they're not causing problems due to inexperience.

You speak really good English for it not being your first language, btw.