I read about a bio-feedbak experiment once where they hooked people up to a BP monitor that would ring a bell everytime the reading went from below a certain value to above that value. They offered people $5 for every time the bell rang.
There were people who learned to just make the bell ring constantantly.
It might not be their cuff. It might be your response to having your BP measured there.
It’s having my BP measured with an automatic cuff. Instead of stopping if the BP is “high” it will deflate partially, then inflate again and each time it does that, it gets tighter and the BP goes up. I had one give me a bruise around my arm, but the medicos wouldn’t take it off. Then a doctor came in and told them to use my forearm or my calf.
I told the last techy that, but he just readjusted it. I ripped it off my arm. Stupid helper.