Thank you Adam for your very thorough answers and your thoughts on this. Much appreciated!
Based on yours here's what I will adjust in my process:for my well-behaved CMOS - stop using Bias frames as such and focus only on FlatDarks for my Flats
use …
Thank you Adam, I didn't find any solution on the PixInsight forum unfortunately, except a piece of user advice (resizing your PI window and then going fullscreen) which didn't work for me. I will contact them about it