I've had a similar issue with menu displays, and it's a bit puzzling that this bug seems to affect only some people and not everyone.
Perhaps it's tied to screen resolution or even the specific web browser they're using ?
It's a bit of a mystery, especially considering that when I'm working with the Gdevelop game engine on my computer, everything runs smoothly ( even when I adjust the game window size during play, it adapts perfectly )...
I can't say for certain whether you'll encounter these menu glitches on my official game page ( https://xigame.itch.io/switch ) to see what I mean.
However, I did manage to find a workaround by exporting the game as a ".exe" file ( which I placed on a different page due to some restrictions during the game jam : https://xigame.itch.io/switch-exe ).
It could be worth giving it a shot to see if it works for you as well !