Does your Fitbit HR when going up stairs read super low randomly?

tarisa01

So when I go up a few flights of stairs (I live in a coulee so climbing up the coulee stairs) where my physical heart rate is at like 185 or even higher, my Fitbit versa reads as like 110 or 108 or 96 BPM, but when I stop and take my actually heart rate manually, it’ll be 185 or whatever it really is. My Fitbit doesn’t do this when I do jogs or anything else that gets my heart rate up really high lol. Any ideas as to why this is happening? Anybody else’s do this?