For those encountering a similar issue to that described in the original post - I have found a solution that may be of relevance. I was using the 'external_choices' tab in my xls form as I was using a drop-down list that was some 5000 items long. However, when trying to view the value for that field in a submitted record in the Inbox, that field was showing up blank. Instead I added this list to a separate csv, saved it in the media folder for that form and then redirected the form to read the list from the csv as opposed to the external_choices tab and when I republished the issue was gone.
