I wish they could have made this indicator/notification pop-up optional, along with the reaction feature.
Experiencing this very annoying bug on iOS 15.4.1, iPhone XS Max, Telegram 8.7.1. I also use the macOS native client (8.7.229824 AppStore)—I wonder if it's a cloud syncing problem. It's been appearing for months. Previously I could fix it by manually scrolling up to the culprit reaction without tapping the button, the animation would load and the notification would stop reappearing. This doesn't seem to work to me anymore, as of today.
Same for me. Used to work, but after the reaction is pushed back too far, it becomes impossible to mark as read.
I have however noticed that if you wait even longer, at some point they don’t show up anymore. However, in the meantime, new unread, unreachable reactions have happened already. Extremely annoying. Happens only with very large chats (few hundred to few thousand messages a day)