CJW said:
Bree, I do indeed have version 1709.
The problem has resolved itself ... somehow & IE is no longer opening on it's own.
My guess - previously you'd sometimes shut down without bothering to close IE. You are now so sensitized to IE reappearing you religiously close it before shutting down, Try leaving it open the once and see what happens.

This new 'feature' in 1709 has had little or no publicity, it has already confused a lot of people. :)