Invisible replies/likes/follows?

I made a new account a month ago and I've been getting weird invisible interactions. Sometimes I see that one of my posts has a reply or a like, but when I try to see the reply or the likes, nothing shows up. I've also gained a couple followers, but when I look at my following list, there's nobody new. (I don't get a notification for any of these, either.)

Does this happen to anyone else? Is it bot activity? I've been chalking it up to the site just being glitchy as always, but is there any actual reason for this?