Help me use background recording in xml

1. What is the problem? Be very detailed.
I have built a form in odk build. it has follow up questions. when I export as xlsForms, the follow up questions do not turn up where they should. If I other wise try exporting into xml, it works. now, I want a background recording, this I see only in xlsforms. how do I do both the things, use follow-up questions as well as use background recording? if something to add in xml code, I can do if tought

2. What app or server are you using and on what device and operating system? Include version numbers.
odk collect 1.30.1; central 1.2.2; and build.getodk.org

3. What you have you tried to fix the problem?

4. What steps can we take to reproduce the problem?
add followup questions using odk build, export the form to xlsForms then upload on central, same symptoms reappear.

Can you attach your Build form or your XLSForm? If you'd rather not share those publicly on the forum, you can email them to support@getodk.org.