classic relay ghost story. reactions are separate kind-7 events, so an unlike only deletes YOUR copy and stale ones keep floating until the client reconciles by re-querying the e-tag. worth logging wh...
That actually gives me another useful test idea. I could log which relays receive the kind 5 deletion and then check which ones continue serving the original kind 7 reaction afterward. That would make the problem much easier to see instead of just watching the reaction count change in the client. Maybe this is something worth turning into a small relay test tool too. Nostr keeps giving me new rabbit holes 🙂