How to control tempo with footswitch

Hello, just got my beatbuddy mini2 yesterday, still in the learning phase of course, one thing i couldn’t figure how to do is changing the tempo with the footswitch. once i reach the tempo section i do manage to change the tempo when i click on it but the numbers i get are random, it just jumps from one tempo to another without any logical pattern so i’m wondering what am i doing wrong? thanks