Not A Bug Upper Hand does not trigger against Quick Claw/Custap Berry

[OBY]

What type of bug are you reporting? Mechanics

What is the bug?
Custap berry and Upper Hand relationship.
Is custap berry suppose to move first against an opponent using upper hand?

Are you able to replicate it? If so, how?
custap berry and upperhand

 

[A Cake Wearing A Hat]

Custap Berry does not grant priority. It simply makes you move first in the priority bracket the move used resides in. It works similarly to Quick Claw in that respect. You are still using a priority 0 move, and therefore Upper Hand will not trigger.