I'm receiving an error when trying to submit a survey saying "Large attachment file is not allowed. Please check server max upload size"(screenshot attached).
I understand AGOL has a 10mb limit, but the largest image is 8mb. Is there a setting somewhere causing an issue?
Is the survey hosted on AGOL or an enterprise portal?
Have you try to submit the same image with web form?
Is it possible to share your XLSForm and the image you attempt to attach?