Guild Wars 2

Successfully killed SB.

Havent killed him character in a week, and on any character in ~2 days.

No chest.

my yellow went right into my inventory, no chest but i had a level 70 rifle on my level 36 toon, that wasnt there before

I have the same problem when doing the event with my mesmer (level 17).
I see the big chest, which I can loot from but I do not receive the little one that appear on the screen above the map. I do not have any new item in my inventory (except from what I loot on bodies). I did not kill the behemoth for two days between theses bugs to be sure the timer was resetted

Only character with level 40+ will receive the bonus chest.

However, there are some issues where players did not receive the normal boss chest.
Just a few threads about that issue which is not addressed/ communicated by Anet yet.

You can have a look at that for example here:
https://forum-en.gw2archive.eu/forum/support/bugs/World-Boss-Bonus-Chests-Not-Always-Appearing/first
https://forum-en.gw2archive.eu/forum/support/bugs/World-Boss-Chests-Not-Appearing/first#post1885151
https://forum-en.gw2archive.eu/forum/support/bugs/Fire-Ele-bugged-didn-t-receive-chest-or-bonus/first#post1867808

I think I figured it out.. if you camp your character at a certain boss and do nothing (like an event) between both times when you kill the boss, you will likely get no chest (but you will receive the golden medal).
Say you would have done a pre for behemoth (killing the portals), you would have reset and would have been able to fight against behemoth AND receive his boss chest.

This also happens a lot more to other bosses where you can easily miss pres (in case you camp there and only switch to this character when the timer says the boss event is active) like Tequatl, Shatterer, Jormag, …

To prevent this, you could:
a) rotate your characters: switch to another character each day
b) do pre events before killing that boss with the same character
c) kill and do other things in between and don’t wait just for the boss

Well, in my opinion it shouldn’t be that way. It should always automatically reset after 24 hours (real life time, not gaming time). Preventing botting is fine, but it hurts the legit player.. sometimes it happens that you come there and kill the boss and were not able to switch characters or do pres before.. but how can it be that you will be punished for doing it the first time each day?
Doesn’t make a lot of sense at all…