Thanks for all the replies.
I read the owners manual as soon as I got home from the dealer, which was no short drive, the dealer is 130 miles away. I broke out the manual because after driving my 2017 for 4 years my noggin told me things were not the same. I did take it back to the dealer to be checked out and got a 2021 loner. The BSM operated the same way as the new 2021.
This morning I was notified to the results that I already knew, they found nothing out of the parameters put out by Mazda. On my way back to dealer I experimented with the system and have concluded that Mazda must have made adjustments to the speed censoring formula between your car and the one you are passing to determine if the BSM needs to be activated. If you pass a car on the right that is moving at a speed slower than you by a certain miles per hour the system will not activate. If I slowed to 70mph the BSM system activated on all traffic I passed on the Interstate.
I drove 46000+ miles in my 2017 and most was highway miles, of those thousands of miles I set my radar controlled Interstate speed at 78 mph. I can't tell you 100% that every vehicle I passed the BSM activated but I can tell you that every time I passed a big rig and I looked in the mirror it was lit up. If it was just me that noticed this I would let it pass, but my wife who drives much slower than me said the same thing after her first drive on the Interstate.
And for sure the rear view mirror is still there and I use it, but the rear seat head rest partially obscures the view out the back window on that right side passing situation.
This car also does not set off any alert when people are moving behind the car in a parking lot and it is put into reverse. My 2017 did.
My 2017 was a Cx5 Grand Touring with basic package
My 2021 Cx5 is a Grand Touring with GT premium package
Lesson learned, never expect a newer model of the same car to retain the things you think are perfect.
regards
Jerry