Hey @Maxoumi! Welcome to the Forums!
What kind of elements do you have in your mini golf game? How is your golf ball set up?
In the meantime, I found a thread that can possibly give some insight into changing your actor’s gravity as an option:
[Question] Is it possible to change the gravity scale for a static mesh or Blueprint?
Another option you can to is a bit of smoke and mirrors, where you adjust the angle of the wall’s collision or even add some invisible collision above the ball at points where the possibility of bouncing up exists.
I hope one of these solutions is what you are looking for!