Here’s the issue in more detail including details of the missing WaterBodyCollision profile from DefaultEngine.ini: https://forums.unrealengine.com/t/5-1-water-buoyancy-not-working/720788/11
Here’s the issue in more detail including details of the missing WaterBodyCollision profile from DefaultEngine.ini: https://forums.unrealengine.com/t/5-1-water-buoyancy-not-working/720788/11