APO...sous vide temperature fluctuations

I have noticed that the sous vide temperatures, both with wet and dry bulb, are sometimes ranging between 4-6 Celsius both above and below the set temperature. This seems a bit excessive given that it’s only suppose to fluctuate 0.3 Celsius in sous vide mode. Anyone else having this issue? Thanks

I actually don’t think its an issue. I think the net effect is temp target at the food.