We have a template excel file.  On the approval tab we have 5 different checkbox variables all set up the same way. when a user checks all the boxes one of the boxes will uncheck itself after the user saves the updates, and then clicks onto another file and back to it.  We can not seem to figure out what is going on, since the other 4 checkboxes do not do this.

Any ideas or suggestions? 

Doesn't matter if the variable is edited from the custom properties or the datacard, the checkbox does not keep the change.