Thanks for the tip - I finally got around it another way which which I think was suggested somewhere in this thread:
I subscribed to the Xbox game thingy, $1 for the first month (will unsubscribe before the second month) and started "Play" the sim through this. It immediately went into an update, asked about disabling Windows defender and worked fine after the update was
done. This install has been the most difficult and ridiculous of anything I have ever experienced. It's hard to believe a company like Microsoft launched the sim with so many flaws in the first place.