Static lighting issues with foliage

The user reports a scene with a reasonable number of foliage instances renders with black lighting:

After updating to 4.11 (.1 or .2 doesn't matter) I have not been able to bake my lighting properly with an external scene of mine, all the foliage looks really weird, no matter the render settings.
On 4.10 I would have some issues but eventually it would work, but now it always renders like this:

Note:
Not all tress are using foliage, the ones that look fine were not placed using foliage.
The render in question was done on production quality, but I've tried with preview as well.
The scene has a skylight and a directional light both static, there are some more static lights inside the building.
The resolution for the foliage is set to 8, but that was me trying new settings, before the trees would vary from 16 to 32 (and it worked fine on 4.10).