Filament - no shadows, raytracing issues

wolvesandlambes

Filament works fine when it comes to textures etc. But it refuses to create any shadows (I have followed tutorials, applied raytracing etc in the shadow settings.) Adjusting parameters in Tone Mapper options, Enivoroment node options and Filament Draw options makes no difference to the image.  Another quirk is that if I change to another viewport, I can only reactivate Filament viewport if I reset my workspace layout. Not sure it that's related to my problem with shadows. Any advice would be appreciated, thanks.