I am someone who almost never uses the slide-bar. When I raise and it’s not minraise, halfpot or pot I enter my raise in. Usually its a multiple of the Big Blind.
But sometimes entering your raise causes issues.
Take this hand: #829038023
At the river I wanted him to bet all his chips. Unfortunately I wasn’t aware that I had a shorter stack than him. So I entered more than I had. But this caused the Raise-button to grey out. I realized that the attempted bet was larger than my stack, so I clicked on the Max-button. But the raise button stayed unclickable. I panicked because I wasn’t able to fix the Raise-button, so I didn’t think to at least call. In the end I timed out.
A quick testing in another game showed me that none of the grey buttons above coulf fix this. But after you move the slidebar can click again on the Raise-button.