Why doesn't Annie's Bear increase HP or damage on level up?

It's been a while that Annie's Ultimate, summoning a bear, doesn't do what it is supposed to upon leveling up. Does anyone know why?

Solution 1:

I don't know if you mean its not leveling when you level the spell or what, but here is what's supposed to happen. Every time you put a level in Summon: Tibbers he increases in HP, Damage and his Aura (not to mention cost to summon):

• Cost: 150 / 200 / 250 mana.
• Magic Damage: 200 / 325 / 450 (+0.7 per ability power)
• Tibber's Health: 1,200 / 1,600 / 2,000 health.
• Tibber's Damage: 80 / 105 / 130

Solution 2:

Changes to Tibbers as of League of Legends v1.0.0.140

• Cost: 125 / 175 / 225 mana
• Summon Magic Damage: 200 / 325 / 450 (+0.7 per ability power)
• Attack Damage: 85 / 105 / 130
• Health: 1200 / 1600 / 2000
• Armor: 30 / 50 / 70
• Magic Resist: 25 / 45 / 65