I had a 2 week period where my BP and pulse were similar. I attribute it to severe neck inflammation. I had ridden in a car and slept with my head hanging forward for almost 2 hours. I could hardly get up from sitting.

I resumed good sleeping posture and iced my neck and it resolved over a few weeks.

By definition, it is an autonomic nervous system issue. Brain stem inflammation can be the cause.

Dehydration can be a factor.

Did the doctor ask you to do any physical exertion to see if it changed it?