What type of bug are you reporting? Mechanics
What is the bug?
A Mimikyu holding Red Card normally activates the item when it's hit by any attack, even through disguise, but a Landorus is able to ignore the item's activation for some reason.
Are you able to replicate it? If so, how?
I tested this with the person I found the bug against. A Mimikyu holding Red Card won't have the item activate when hit by Landorus, even if its disguise is already broken. The Landorus in question had the ability Sheer Force and was holding a Life Orb. Even testing with Conkeldurr, another Pokemon with Sheer Force, it was switched out as should normally happen. I have no idea what specifically is causing the bug, but it's consistent throughout our testing.
What is the bug?
A Mimikyu holding Red Card normally activates the item when it's hit by any attack, even through disguise, but a Landorus is able to ignore the item's activation for some reason.
Are you able to replicate it? If so, how?
I tested this with the person I found the bug against. A Mimikyu holding Red Card won't have the item activate when hit by Landorus, even if its disguise is already broken. The Landorus in question had the ability Sheer Force and was holding a Life Orb. Even testing with Conkeldurr, another Pokemon with Sheer Force, it was switched out as should normally happen. I have no idea what specifically is causing the bug, but it's consistent throughout our testing.