Reporting API only gives back Custom Variables Categories when using csv format

Im trying to get data about the Custom Variables I’m tracking. When I use


&format=json

in the queryUrl, this gives me the subtable for every Custom Variable category (name) including back nb_actions and nb_visits for all variable labels (values) per name.
When I specify


&format=csv

I only receive the aggregate numbers for the categories (names) of my custom variables, without the breakdown of individual variables (values).

Btw, these are all the request parameters I specify:


url += "?module=API&method=CustomVariables.getCustomVariables"
url += "&idSite=3"
url += "&period=day&date=%s,%s" % (fromDate, toDate)
url += "&expanded=1"
url += "&format=csv"
url += "&token_auth=%s" % token_auth
url += "&segment=%s" % "pageUrl==%s" % pageUrl	

Is there a way to get all data per individual variables in CSV format?

Thanks for the feedback, I created a bug report at CSV export with expanded=1 does not export the subtables · Issue #4925 · matomo-org/matomo · GitHub