Data.json vs cvsexport

Hi,

I’m using API to get historical data
I do not understand why :
https://xxx/feed/data.json?id=120&start=1586464200&end=1586489400&interval=1&skipmissing=1&limitinterval=1
=> get NULL, empty,
https://xxx/feed/csvexport.json?id=120&start=1586464200&end=1586489400&timeformat=1&interval=1
=> get 14 values (not empty!)

thanks !