IBTS graph all over the place for back to back roasts of the same bean

Hi,

i have been having ths issue since i started doing back to back roasts.
a syou can see in the graphs attached. the roast time and quality seems to be the same but, the profile curves go mental :sweat_smile: as i continue the back to back roasts. Also all my curves seem very noisy to me… is this normal?

i have no idea why this is happening

thanks