@mitu Thanks. I think I found the problem.
This is my retroarch.cfg (taked from the previous version of my Retropie (4.3.1.2.):

# Settings made here will only override settings in the global retroarch.cfg if placed above the #include line input_remapping_directory = "/opt/retropie/configs/gb/" # 19 = Config, 20 = 1:1 PAR, 21 = Core Provided, 22 = Custom Viewport aspect_ratio_index = "22" # these two define the pixel size of the emulated screen # keep this in the same ratio as the original console # eg: GBA 240x160 * 3 = 720 x 480 custom_viewport_width = "480" custom_viewport_height = "432" # the following two decide how far from the left and top the game screen is shown # to centre the game display use your original resolution, minus the screen size, divided by two # this example for 1080p screen (1920x1080) # (1920 - 720) / 2 = 600 custom_viewport_x = "400" # (1080 - 480) / 2 = 300 custom_viewport_y = "324" #include "/opt/retropie/configs/all/retroarch.cfg"

I modify Custom Viewport aspect_ratio_index from 22 to 23 and now screen size is correct.

Thank you very much.