@MonoDeaf Luckily, a helpful discord user resolved the issue.
For individually placed trees just turn on WPO in ray tracing.
And for trees painted in foliage mode type this into the console:
r.RayTracing.Geometry.InstancedStaticMeshes.EvaluateWPO 1
In path tracing mode the trees will be blurry while they move, this is normal. When you render them out via movie render que the blurriness will be gone.