Since a recent Windows 10 update, about end of September I constantly get the Windows Security question popping up: Select Certificate. Design of message is new Win10. I have the certificates since a long time.

It propose sany of my certs in random manner, iPhone to one the email certs or cert for signing PDF.

Which app fires that question? IE/Edge my guess, Outlook.. Firefox.
How to disable?

Bad UI design, no context shown.

I've only found older reports on IE, which didn't helped:

Thanks for directions.