Hi! After a massive support from you all, decided to bring some fresh updates based on the videos that you shared. Previously in the game "this.vertical" and "this horizontal" were used to handle character movement directly from its behavior, which, due to some specifics of the "onKeyEvent" method from the behaviors class, caused movement to stop under certain conditions of holding down extra keys. In some scenarios, this could simply stop the character's movement during frame rate drops. As a result, the vertical and horizontal axes for movement are now determined in the main preload behavior, which passes the direction axes without being affected by the frame rate or any other key presses during movement.
If any other issues occur, don't hesitate to comment. Thanks to all!