Thats not a solution. What you did is the worse possible thing you can in fact do; look up Ark Meshing for an explanation as to why.
Go back to the drawing board.
Open up your mesh. Withing the panels find the collisions.
For a simple floor tile - set the values to 1 poligon with 8 verts and click generate - or just manually add a collision box and set the size of it appropriately (boxes cost less performance wise).
Ensure the collision is thick enough for the smallest object you want to support at its maximum travel speep (general rule of thumb is at least 10cm thick).
With that, you now have collision set up.
All you need to do is assign the object to the correct collision profile.
A floor tile is likely just WorldStatic.
Thats it.
Once you push the tile into any level from then on - unless you mess with the tile’s settings specifically - it should automatically just work.
If you are making your own geometry, look up how to export UCX and UCB along with your FBX so that you do not need to babysit the engine’s collisions upon import.