Changes to the Navigation settings aren't saved when edited in the Static Mesh Editor. The values will reset back to default values when the asset is reopened.
1. Create a 3rd Person project & open it (any project with existing static meshes will do)
2. In the Content Browser, find the "1M_Cube" & open it
3. In the Details panel, scroll to the bottom > Navigation > Enable "Is Dynamic Obstacle" and "Gather Convex Geometry"
4. Save & close the Static Mesh Editor window
5. Reopen the asset
6. In the Details panel, scroll to the bottom > Navigation
Results: At least one of the checkboxes that were enabled will no longer be checked. This also happens with Cylinder Collision and Box Collision array values. The values will reset back to default values when the asset is reopened.
Expected: For all changes in the Navigation section to be saved
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-43248 in the post.