Raspberry pi4 scaling issue

Thanks for the update, I'm closing again.

So the problem seems to be in my display .-.
Into the display's box I found this paper where there is a difference between video input that could be 1080p and effective Display resolution that is 1024*600.
I tried the others resolution setting into weston.ini -> mode=<resolution> but none seems fine.
I have to change the display .-. Thanks

indeed, check out the ini file to see if the name of the output matches

What might happen is that panel is 1080p but the preferred modeline to be 720p. Have a look the compositor log (journalctl -t agl-compositor) and figure out the preferred vs current resolution for that particular output. Then check out the [output] section in ini file and verify that the connector head name is the same as the one that you saw in the compositor log.

If that still doesn't work please attach the entire compositor log and ini file.

  I'm reporting the specs of my display that shows that supports as maximum 1920x1080 so has to support 1080p. I will check resolution in weston.ini and update this comment. Display

Are you trying to use something other than a 1080p resolution screen?  If so that has not been supported since this issue was marked resolved originally.