Hi Turbo! Welcome!
I have not seen your code, so I am stumbling around in the dark a bit.
(Yeah, I have heard the jokes about my sex life being like that, and they hit too close to home, thank you)
Anyhow....
Choosing a button by outerhtml seems to me like a recipe to failure. Especially with wildcards, the odds are high that the same code can be found several times on the site. That way, uBot might have been lead to a different button and clicked it happily, although in vain.
::emp::