17.3 / banner.jpg not loaded upon add

I run 17.3. I have a series “Samvidhaan”, about consitution of india. I made an NFO using tmm. Using some paint-like program i created a banner for this (as no banners available on tvdb). After creating the whole metadata set inclusing posters etc, i added the movie. Kodi wouldnt load the banner.jpg, which it should always do, according to the docu.
What is going on here?

Sent from my iPhone (typie typie)