Hey Rens2Sea,
Take a look at Material assigned to your ball’s Mesh. In Details panel, you can set a Physical Material for that Material. To create your own custom Phys Material to use here, right click in your Content Browser (or click New) and choose Physics > Physical Material.
Open up Phys Material, and you’ll see settings for Friction, Restitution, and Density. If you set your Restitution higher, you’ll get more bounce from Actors with this Phys Material assigned. Try 1.75 to start with and adjust from there based on your mesh’s settings.
Hope that helps! Let me know if you run into more questions with this.