Recently made an arduino coupled popper. It all works well, connects and controls via Artisan.
I'm trying to run a background roast and let the controls be governed by that roast. That works well but the problem is that whenever I start the roast (simulated) the temperature scaling changes.

I've included two images, one before the start button is pressed and the other one after the button is pressed. Clearly the point at 160 degrees C is scaled down to below 150C. The roast will follow the (wrongly) scaled background perfectly but this is not the right roasting profile.

Anyone has had a similar issue or have an idea on how to resolve?