ODK collect / repeat index help

I have a form, i want to display a calculated summary of a loop value at the end, and used index repeat. the issue is "it works when all loops values are fully filled, if one loop values is not filled, it will not sum up the values.
I am using the latest version 1.16.1 of odk collect.
I am attaching the form, minimizing some questions. i have a loop of 7 cluster which is fixed. inside loop there are missed children details. for some cluster there will be no miss children, hence at the end there is a summary which will sum the values of all 7 clusters but as some cluster have no miss children, so it will not show the sum.
IntraCampaign_HH_cluster_NEAP18_19.xlsx (41.7 KB)

Set a default value '0' to each integer field inside your loop, it does not affect on your calculation if your enumerators do not put any value, if they have any value to enter, so they can replace it with '0'. you can set a constraint to accept values only greater than and equal to '0'.

Dear it is already done in the attached example form

in addition, when i test it on Enketo, it gives the sum but when i use odk collect, it don't gives the desired result