Dear Vymuell, Hirnsushi and Ingo,
Thanks a lot for yr suggestions. When I learned of the Win10 issue with fastboot, I decided to take the Linux route. Following the instructions at How to Install iodéOS 3.2 on a Fairphone 4 for Dummies - Brotcast (from AlphaElwedritsch on this Forum?), my FP4 is now “Bien Iodé”.
Greetz