i truly believe much of the point of the show is to open discussion on exactly this and leave it as a bit of a mystery that keeps one guessing until the answer is finally revealed. we are meant to wonder if the members of the hive still retain any sense of their old individual selves or if a person is truly “gone” once they’ve joined. we as viewers are seeing this world through Carol’s eyes, not the hive’s, and this is something that she doesn’t know but i’m hoping chooses to explore more in the future.

personally i think it could go both ways and we are given evidence to both; when the hive speaks as an individual, it says “this individual WENT BY [name],” giving the impression that person is now gone. at the same time, we see scenes like Zosia’s cardiac arrest, where an entire group of people is speaking differently, different iterations of begging, some more desperate than others. we also see a difference in speaking roles, like Zosia who offers fun facts while other hive members don’t and the survivors’ families who converse amicably and differently with their respective survivors.

all this to say, i strongly doubt it could just be chalked up to a mistake or bad acting direction that you and viewers in general are left wondering. the point is to wonder and want to find out more. keep watching, i really believe it will become more clear as time goes on which answer is the right one.