Thank you for your comment! Tbh we don't know why Unity made changes in the scene after building the project. The original canvas scale of the game was conserved, but the camera scale was cut off. The texts were also moved from their original place after building the project and it made the game confusing for the users. It was supposed that the menu, level 1 and level 2 would completely fit the screen and that there shouldn't be any problem :(