[Gameplay] Thunderlord's Decree AD Tab Tooltip Issue

Server: North America Reproduction rate: 100%

What's supposed to happen: When tabbed in a match, hovering over a keystone mastery will display its effects. Thunderlord's Decree is no different, plus it displays how much damage it does with your current AP and Bonus AD. In the Masteries page, hovering over Thunderlord's Decree will display that 20% of your bonus AD is applied to this keystone.

What ACTUALLY happens: When hovered over in the tab menu, the Thunderlord's Decree tooltip displays only 10% of your Bonus AD. Whether this has an effect on the actual damage dealt, I have yet to learn, but this doesn't match what the two tooltips state.

How to reproduce: Set Thunderlord's Decree as your keystone mastery. Go into a custom lobby, check the tab keystone tooltip, and buy an AD item. Intended effect: The number increases by 20% of that item's AD. Longsword should add 2 to the damage tooltip, Doran's Blade 1.6 damage, and Cull 1 damage. Actual effect: The tooltip increases by only 10% of that item's AD. Longsword gives only 1 AD, Doran's blade only provides 0.8 extra damage, and Cull only gives 0.6 extra damage.

EDIT: The AD and AP scalings for the tooltips are flipped. On the AP side, Doran's Ring and Dark Seal are only supposed to add 1.5 damage to the tooltip, and Amplifying Tome is only supposed to give 2. Instead, they add to the tooltip by 3 and 4, respectively.