Our users are having this problem while trying to send completed surveys. I checked some topics related, that says the problem might be the length of the fields, but the formulas we´re using in this form are just minus operations. I attached the form and two pictures, hope you guys can figure it out and help us.
PS: in the next update, we´ll change the fields 'Prof_recomendada' and 'Esp_recomendado' to integer/decimal and remove the limit of characters/input mask. Gonna wait for your recommendations to add other necessary changes.