Extended dimensions set doesn't return data - request

Question

I want to pull a number of metrics from Google Analytics API with "Traffic Sources", "Geo Network" and "Audience" dimensions.
So I create the following request. GA Dimensions & Metrics Explorer shows that these metrics & dimensions are compatible. But for some reason, this request returns zero values:
{
"reportRequests": [
{
"viewId": "xxxxxxxx",
"dateRanges": [
{
"startDate": "2020-03-01",
"endDate": "2020-03-11"
}
],
"metrics": [
{
"expression": "ga:sessions"
},
{
"expression": "ga:newUsers"
},
{
"expression": "ga:transactions"
},
{
"expression": "ga:transactionRevenue"
}
],
"dimensions": [
{
"name": "ga:date"
},
{
"name": "ga:campaign"
},
{
"name": "ga:sourceMedium"
},
{
"name": "ga:country"
},
{
"name": "ga:region"
},
{
"name": "ga:city"
},
{
"name": "ga:userAgeBracket"
},
{
"name": "ga:userGender"
},
{
"name": "ga:interestInMarketCategory"
}
]
}
]
}
Although restricted dimensions set shows that data exists:
"dimensions": [
{
"name": "ga:date"
},
{
"name": "ga:campaign"
},
{
"name": "ga:sourceMedium"
},
{
"name": "ga:country"
},
{
"name": "ga:region"
},
{
"name": "ga:city"
}
Why extended dimensions set that shown in 1st example doesn't return data?
Thanks in advance!
Eugene

Answer 1

May be GA doesnot have any information about the user age, gender and in-Market segment (ga:interestInMarketCategory). So when you add these dimensions with others, API returns data for the combination of specified dimensions.
So let's say there are 20 sessions from combination of city = x and region = y. But when you add gender to it, no combination can be made (e.g. city = x and region = y and gender = ?), hence API will return zero response.