[luxor]

hamlet explained me why it doesn't work :
killed pre -> deadflag = 1
spawn pre -> deadflag= 1
spawn post -> deadflag = 0
killed post -> deadflag = 1

so... it is not an amxx issue...

[Arkshine]

Hamsandwich is essentially a wrapper around virtual functions of game. it does nothing else than executing/hooking game functions. No custom code. Issue is about game knowledge.

Best way to respawn a dead player is to use wickedd's way, DEAD_RESPAWNABLE + think. Player will respawn 0.1 second later.

pev_deadflag is always reset at spawn, so this is unrelated.

Explanation is likely similar to what KliPPy said. You are marked by the client as dead from DeathMsg and ScoreAttrib message.
DeathMsg uses MSG_ALL and ScoreAttrib uses MSG_ONE. I don't remember exactly how engine works, but if I'm right, when saving messages for current frame, MSG_ONE has the priority before the global one. So, it would make sense that client would receive DeathMsg at the very end of the current frame, and thus client would be still marked as dead at player's spawn.