Apple Watch - 1 low reading

Does anyone else have an Apple Watch and it does this one low reading? Mine does not do it every day but most days. I think it’s happening when I either corchet, get up (I use my hands to get up) and then my arm work out where I use my wrists. It only happens 1 time a day and it’s normally 60-70, but today was 45. And in the same minute or the next it will jump to what’s normal. I have hyper pots and ist, and the 24 holter, ekg, and tilt table didn’t do any of this. And when I had a similar issue with the visible band I took my finger reading and it was higher. So idk what it is or if it’s an issue with the watch? Anyone else have these issues?