Hi, I was doing a game today, and I tried tanking blue buff with Tibbers. Tibbers passive killed the bluebuff golem, and I didn't get the buff.

I thought this was some sort of missconception, so I tried it again, this time on red buff.
The exact same thing happened.

Repro:
1. Pick Annie on SR.
2. Get to level 6.
3. Have Tibbers tank any transferable buff monster.
4. Leave him tank the buff but leave his aura kill the buff holding monster.
5. Look at both: your champion, and your buffs/debuffs. There won't be any buff.

I was using AP jungle masteries with MPen Reds, Armor Flat+perlevel Yellows, AP perlevel Blues and Movespeed Quints.

Idiot the buff gets taken by the killer itself. Besides if any champion's ult is like annie's then the same case happens. But this case doesnt occur to champions like heimderdinger's turret or zyra's small plants because that is their ability itself and they cant move it. FYI if u summon controllable units wid ur ult ans thet kill the golemn then they get the buff like tibbers. Note that this case wont occur on shaco.

this is definately a bug i have had tibbers tank blue for me several times after a team fight and i always got the bug(i have not played annie since her model rework)

That is an old bug that keeps coming back again and again. It seems riot wants to test the community or maybe someone in their team wants to make annie worse than she should be. But it is a secret why this happens again and again for years now.