Hey there @ruigol! In most cases, I would recommend adding the Cvar to your DefaultEngine.ini but it seems the framerate command doesn’t seem to work in it correctly from my test.
I believe packaged games use the Game User Settings first, which would be why other methods don’t initially work. You could use the built in Getter and Setter for Frame Rate Limits and this should persist through sessions:
Alternatively a quick workaround (viable in editor) while I’m working out why that is would be to run the command t.maxfps 120 at the start of the runtime instance and it should remain that way until the instance ends.