Sometimes the landscape collision does not work

I’ve an actor which the collision is set to worldDynamic, and a Landscape. I set to true
‘generate overlap event’ in both the actor and the landscape. However sometimes there is no collision happening, maybe about 20% of the time the collision does not work. I change the ‘simple collision mip level’ from 0 to 2 and it works more often but still not working 100%. What’s happening?

Please post a screenshot of both objects collision settings.

Hello. What I did to fix the problem was to increase the collision sphere size of the actor and now it seems to collide fine with the landscape.