After programming and testing forms succesfully, the field team reported that sometimes questions don't show up when they should. However, I checked many times but everything under 'relevant' is correct, moreover I tested the forms and they work correctly for me.
Trying it a few times, I notice that also on my tablet sometimes whole questions or groups are skipped. But when I start the form over (without changing anything or even without re-running it through xlsform), it suddenly works perfectly again, or other questions are missing. Basically I never know what will happen, but often things are missing and we can't have that in the field. I'm a hundred percent sure now that it is not faulty programming.
I am programming in excel, using xlsform offline and odk collect --> latest versions.
Has anyone encountered this problem as well? What can it be? Is it because my forms are very long?