The post process lens flares are not generated on light sources as they were in previous engine versions. Instead they are generated in high intensity areas, which is more physically correct. The values you were tweaking in that video are only relevant if there would be a flare, but it seems like everything in your scene was to dim to even generate one.
To test if this is indeed the issue, create a light with a very high multiplier and place it very close to an object to generate a blown out spot, this should generate a lens flare.
There is no lens flares in any form in my postprocess volume. I try with many different bokehshapes and other options. No matter what I do, there is no lens flare in the scene. Postprocess works fine in other aspects. For example, bloom and dof, works perfectly fine, but lens flare doesn’t.
Here is video that shows this issue:
(This red emissive is particle system with bright, red material)
Unfortunately, looks like solution you suggest doesn’t help. I’ve restarted the engine, and try it on different map.
Same thing. Everything in postprocess volume works, accept the lens flares. I’ve added very bright light, close to the meshes and use default bokeh texture - still no effect.