In my experience, this is normal for being part of a group, that group-iness brings this out. If you asked many group members what they think, most people would say they are the marginalized ones and that others are treated more favorably than they are. Those who do not feel slighted might not have grown up in dysfunctional families, or they are particularly strongly defended (but of course I'm always the favorite one!) or they are more avoidant and want to be ignored, so they don't notice or it doesn't feel bad to them.

It's possible that both things are true, that it is partly your filter/lens that is making you feel less responded to, and maybe the T is responding to you for reasons that make sense in terms of the group dynamics. Such as, perhaps you say more in your comments than other people, where others need to be drawn out for their meaning, and that's why there's a dialog. I'm not sure (haven't studied therapy in particular and not groups), but I think the ideal is not for the dialog to be between leader and group, but group members.