That happens for some reason when people react to replies. The reacts trickle up back to the original note. I think it's something to do with how Damus handles react events.
Discussion
Im 99% sure this is a Damus thing nostr:npub1zafcms4xya5ap9zr7xxr0jlrtrattwlesytn2s42030lzu0dwlzqpd26k5 has this been brought up before?
Understood. Ty