FT.AGGREGATE returns all lowercase

I have a very weird problem. I have a project that I develop with Docker in my local machine using the latest stable RediSearch image. In production Redis and RediSearch are installed normally in an Ubuntu server. In both cases, the versions of both Redis and RediSearch are the same (the latest).

In my local environment, a simple query of
FT.AGGREGATE posts “@post_id:851” LOAD 1 @post_object APPLY @post_object AS post_object


Returns just what expected it to. But in the production environment, the post_object field is converted into lowercase. If I do a FT.GET to the document itself, it shows normally with the uppercase letters.

I haven’t been able to find any differences in the configurations between the environments. Does anyone have a clue about what could cause this? The index definitions are the same in both instances as well.

It’s probably because post_object is a SORTABLE field