Recently-played endpoint behaving weird

[FBelardi]

Hello everyone, I am working on this endpoint: https://api.spotify.com/v1/me/player/recently-played.

I was wondering how much delay there is between the actual track listening (via UI) and the presence of the data in the API response. To check this in a precise way I created a new Spotify account (non-Premium) and I did the following:

1. listened to track A;
2. saved track A;
3. listened to track B;
4. [24h stop];
5. listened to track C,D,E,F,G.

Using the recently-played endpoint, today (48h later) I only see track B but not the others. Of course I can see the saved track (A) using the https://api.spotify.com/v1/me/tracks endpoint.

Did anyone experience the same issue? Is there some documentation I can read to better understand the endpoint behavior?

Thanks F