EAC on btw.
A20.6 have fixed one double exp bug, but there definitely is other one(it existed before A20.6) which I every so often meet on dedicated.
It looks like you get ragdoll of zombie which is still alive, so its twitchy and all... And killing it (tried torch and knife; once finished with bow but got one kill; might have nothing to do with bow, dunno) provides kill twice.
What exactly causes it is uncertain. For me it always involves bleed and may be torch fire. Unable to reproduce reliably (was trying to, of course)
I was unable to reproduce it on single player by playing around with torch and bone knife. It might be just client thinking that zombie isnt dead but server thinking its dead? Dunno. Found https://community.7daystodie.com/a20-bug-database/bug-pool/fire-from-molotovs-lacks-something-r740/ instead of reproducing it, lol.
So its not really a report yet, but keep an eye for it perhaps? It definitely exists (and existed for a long while).
Footage on some Chinese server (had high ping, but I dont feel like high ping helps reproduce it at all):
it is 100% exp, footage doesnt show it but normal reward was 400; I got 800 thus confirming bug still is in the game.
If it helps, when double exp from torch killing burning targets existed, finishing burning target with this state with torch yielded triple exp.
Good idea would be to just cause this state to mobs without having a hard time reproducing; after all it probably is some unit property which makes it appear dead on client?