Description
A light has the property LightBakingOutput.isBaked that determines whether it has been baked or not (which is not the same as its Mode). This property is set based on what is stored in the current Lighting Data Asset — it is never written to the scene file. For example, if the Lighting Data Assets says that light X have been baked, then light X will be marked as having been baked. When using “Bake Probe Volumes” (the drop down at the bottom of Lighting -> Adative Probe Volumes) this property is correctly set in memory but no Lighting Data Asset is generated. Thus, when you restart the editor after such a bake, there is no Lighting Data Asset to properly configure the baked lights. Hence lights are treated as if they are realtime because their IsBaked property is never set to true.
Not only is this confusing to the user, it also differentiates from how lightmaps (or the "Generate Lighting" button) work.
Reproduction steps
1) Create an empty scene with an APV volume.
2) Add a light which is set to Baked. Note that the light still behaves as if realtime. You can test this by enabling shadows for the light and move it (shadows are updated in realtime).
3) Bake using “Bake Probe Volumes” (the drop down at the bottom of Lighting -> Adative Probe Volumes). Note that now the light no longer behaves as realtime (the shadow is not updated in realtime).
4) Restart editor.
Expected behaviour
We'd expect that the light is still marked as having been baked; i.e. shadows don't update in realtime.
Actual behavior
The light behaves as if realtime: shadows update in realtime.
(This happens because there is no Lighting Data Asset to properly configure the light).