Issue with downloading images from folders

Hi all. I work with a large circuit of customers who ask for Hi Res images that my company has stored on BOX. I have been sending password-protected links containing folders to those images, during which I always select “anyone with the link can view & download,” and then the customer should be able to download non-watermarked images. However,  there are a handful of clients that are unable to 1. download the images after entering their password, (they only see “log in/sign up” where the download button should be) or 2. Can download the images, but the watermark is still there. This is not the case for most, but the number of customers with one of these two problems is growing. Can anyone advise on how to trouble shoot and fix this problem?