Hi @Michele Oliosi,
I am experiencing a similar issue currently. I've run two iterations of the same project in two different versions 8.0.14 and 8.0.19. All the parameters are the same.
The Shadings: Electrical Loss acc. to strings in the latest version jumps to 15.1% compared to 4.1% from the previous version. Also, the Inverter loss over Nom. inverter power loss was 4.5% previously which later decreased to 0.5%.
The loss diagrams from both versions are attached. Could you please help with this?