After trying a lot these I finally made it to work.
Follow the steps outlined here and make sure the calculation is correct. The documentation has and error on it for the daily monitoring.
**
calculation is count(instance(‘monitoring’)/root/ data[monitoring/participant_id = current()/../participant_id])
however the correct calculation is:
count(instance(‘monitoring’)/root/ data[participant_id = current()/../participant_id])**
NOTE: “monitoring/" is not needed inside the data[]
another step that wasn’t very clear for me is how to upload the second xsl form with the xml-external and the calculate to self link.
It is form > Replace form > Upload XLSForm.
I also found another support here saying it only works in Enketo, but I tried with Android app and it worked fine. In case anyone is going through that route
I hope this helps. 
