emails in Outlook iOS app show preview, but messages are blank

Recently I've started having an issue that my wife has seen on her phone for some time now. Every once in awhile, with random messages (no common thread of subject line, sender, or content), I will get a message where the preview shows the first few lines of the body of the message, but when I open the message it's completely blank with just a "read more" button. If I tap on the "read more", it just bring up a blank message. These same messages open properly with all the content in place if I look at them in the desktop Outlook client of Outlook on the Web (from the phone or a desktop computer).