Emails not displaying in subfolders

We are having a problem with our email account. I have contacted support but have not yet heard anything back, so I thought I would throw it out to the community to see if anyone has any suggestions.

I have recently noticed that in many of our subfolders that definitely contain emails, none are appearing.

At first I thought it was an archiving issue, but none of these email have been archived, and the unarchive function is not appearing as an option, so it hasn't occurred automatically either.

Then I thought it could be a browser issue, but I tried Chrome, IE, and Firefox, and all have the same issue. Interestingly enough, when I tried it from our iPad using Safari, it appears there are emails in the folders, but they have lost all sender and subject info and you can't actually open them up.

Some subfolders don't have this issue, and I can't find any pattern to the lost emails (as in there is no common date, no common subfolder level, or anything else that the affected folders have in common)

Any help would be greatly appreciated! :-)