Steam in the oven is not always visible when the steam function is running.
If you think that there is an issue with your steam setting, please try the following:
Set the Oven to Sous Vide Mode= OFF, temp = 250F, Steam = 100%. Run the oven for 10-15 minutes, then open the door. Does a cloud of steamy air escape out the top?
If yes, your oven is working as intended.
If no, please reach out to Support@anovaculinary.com