Hey,
The first thing to note is that your vehicle’s box collision seems too big! Make sure it is the size of your vehicle’s body only (excluding the wheels) to prevent it from touching the ground. Take a look at VehicleGame project provided by Epic for an idea on how to set up collision.
Usually, most issues with a vehicle such as sinking wheels or vehicle not moving even though tires rotate are caused by the improper rigging of the vehicle. I’m not familiar with Blender’s interface but it looks like your wheels’ pivots are facing opposing direction! Make sure that the root bone’s pivot and all other bones’ pivots are having their “x” axis facing toward the front of the vehicle as in the picture below:
Image source: Rigging a Car for Unreal - World Creation - Unreal Engine Forums
Lastly, make sure that in your vehicle’s blueprint, under the vehicle setup category > wheels setup, you have added wheels blueprints with their corresponding bone name.
Hope this helps.