I ordered a smart watch that monitors blood pressure.

You also need to do rotevt yourself when changing positions. Standing up, or just turning your head. Go slowly and make sure you have something to hold on to.

Well I guess you solved this yourself. Also make sure you have something to hold onto until you stabilize.

I experienced sudden Blood Pressure drops and ups like a "Roller Coaster", which the measure equipment sent error massages that couldn't measure because of the unstable results. Meanwhile, I was fainting and sent to ER for rescuer.. That happened continuity in three weeks due to the medication adjustment..
Then, I learned get up and sown slowly to avoid sudden Blood Pressure down and up. Keep safe!