This issue has been reported as by Design through the 14.x application.
When personalizing the General Journal page, in this version, the values in the header Group can be hidden.
Unfortunately, as the page has been implemented within 14.x, some of these have the same Name as the fields in the repeater. See below an example.

When hiding the filding in the header group, these fields become available for personalization and have the same header name as the ones in the repeater.
Users might accidentally try to select the unbounded header fields (global variables) and place them in the repeater with unpredictable results.
This is the root cause of this issue.
To resolve it, within this version, you might think of prevent the user to fall back into simple page by
a. Be sure that you do not have any personalization stored for the user for this page
b. Change the OnInit trigger to always use the classic page (and not the simplified one) even with the web client

Worth notice that with version 17.x, this feature has been refactored to cope with show more/less field in the repeater, including the header values already.