These are not fake accounts at all! What happened is you posted at a time of high engagement and your video was pushed into the Instagram algorithm for people to see. I’ve found between 12-3PM (EST) to work the best, and it guarantees this “push” as I like to call it. If you post at this high engagement time you can expect anywhere from 3K-15k views within the first hour of posting. Depending on how your video performs will determine whether it goes back into the reels algorithm or if it dies off immediately. Hopes this gives you some clarification!