Almost all of the social media influencers have an agency running their pages and most of the time it’s not even the US based agency replying, but something called a “chatter.” Typically someone who can speak some English, and is from a low wage country, most often Bangladesh.
There are usually some clues when it is a chatter, some obvious and some subtle.
If you read a message and think “that’s kind of an odd way to say that,” or “that doesn’t sound like a native English speaker,” then you’ll know.