Well, I did not have that daily mission is my version, but I checked this:
org.l2jmobius.gameserver.network.clientpackets.dailymission.RequestOneDayRewardReceive.java
if (player.hasRequest(RewardRequest.class))
{
LOGGER.warning("Kicked " + player + " for spamming " + getClass().getSimpleName());
Disconnection.of(player).defaultSequence(true);
return;
}
ThreadPool.schedule(() ->
{
player.removeRequest(RewardRequest.class);
}, 50);
I think if you press faster than 50ms then you get the kick, because your previous request not removed yet.