Searching items in a folder by content does not search in .json files?

Question

Using the "Content:" search filter under windows 10, i am able to find files that contain a string, this worked for me with excel tables, word docs and simple txt files. However, now i am trying to find a keyword throughout a number of .json files, and i get no returns.

Why is that? I can open jsonfiles with the editor just normally, why cant windows run a plain text search on them? And more important - is there a way to fix this?

I guess i could write a script that just loads the json data and filters the content but... I dont understand why it doesnt work.

EDIT: I already change the indexing to file content btw, and in the list it says that it searches .json files too.