In UEFN, double click on the asset you imported in the content browser. On the right hand side of the screen that pops up there should be a list of settings. Scroll down to the collision settings, and there is a setting you can change so it says “Use Complex Collision As Simple”. Make sure to save the asset inside that screen (save button in the top left of the asset screen) to apply the changed collision setting.
Changing it to that should fix most issues as it will stop trying to simplify the hitbox and instead use the geometry itself to mark where the hotbox should cover, although it’s not a perfect system. You can also click on the ‘show’ tab at the top of that screens viewport and there should be an option to enable viewing simple collision and complex collision. This lets you see where exactly the hit box is and where it is blocking your player.