There’s comparison, enabled visualizing VLM, compared 2 results with PointLight set on Static and Stationary. Static bakes VLM fine, Stationary doesn’t, which confuses me, the documentation doesn’t seem to indicate VLM doesn’t support Stationary.
Or could it be a 4.24 p4 bug?
I answered this with your post in the preview thread, but stationary lights are dynamic in the direct lighting aspect and only contribute to baked data through indirect lighting. Static lights are 100% baked and not dynamic in any way.
Did you have a different experience in versions before 4.24? I can’t say I’ve ever noticed that.
I’ve rechecked again on 4.22.3, 4.23.1 and 4.24 p4. Seems you’re right - on all these 3 versions, VLM doesn’t bake direct lighting from Stationary lights, only Indirect lighting. I don’t know why I was sure that 4.22.3 was baking everything - I’m guessing that at the first I tested in a complex scene and with tweaked Lightmass settings for more bounces, so Indirect lighting might have been looking as it has baked direct lighting. Bummer. I was assuming Stationary light does static lighting on static meshes/stuff and dynamic lighting on Moveable stuff. 
That’s a quite limitation with what can be done with volumetric fog/light…
Thanks for checking in!
Huge limitation! Why is it so?
That is as designed. Direct light is better to keep separate if you want accurate specular highlights.