What causes my 2017 Regal to jolt or lurch btwn 9 and 11 mph?

I would recommend seeing if you can road test a similar vehicle at the dealership - it's possible what you are experiencing is indeed "normal" among vehicles built like yours. If the jolt / lurch is a safety issue, then definitely pursue with the service management of the dealership for more specialized troubleshooting. I think, though, that you'll find it's probably incidental and nothing of any concern.