1600 is the widest, if I'm not mistaken. Does a specific UI element extend beyond the screen, or is it all of them? Because a few updates ago, I was just implementing a new scaling system, and it's possible that I missed some UI elements and didn't adapt them to the new system. Are we talking about specific resolutions? Is this a game running in windowed mode or full screen? I don't have access to screens with that resolution at all, it looked fine during testing, but since you say there's a problem, I must have missed something in the implementation.
At 3440x1440, in fullscreen:
- The main settings menu is enlarged such that the motion blur setting is pushed past the bottom of the screen. The music volume setting is pushed to the top of the screen with the tops of the letters cut off, and the quality setting hovers over the top of the music volume slider.

- The pause settings menu is enlarged such that the quality setting is beyond the top of the screen, and the motion blur setting has half its toggle box visible.

- The pause menu is enlarged such that the save button is beyond the top of the screen.

- The load menu is enlarged such that the "back" and "delete all saves" buttons are barely visible, with their text being outside the screen. This presumably applies to the save menu as well, but I can't test it since I can't click the save button.

That's a lot of information, thanks a lot, bro.
I'm actually working on a new UI layout right now because some new options are coming, and I'm separating the sound from the graphics. I'll take a closer look at what's not working right and try to fix it.
I don't even have that resolution option in my settings xd That's why I was surprised I open the game and thought, “Ultra Wide?” The highest resolution is 1600
I had to set the system to automatically detect certain parameters, and add these resolutions if someone has that kind of setup.
This was done a while ago and it was done in the last 5 minutes before the update, at the fans' request , I must have forgotten about those ultra-wide . Oh well, at least I learned something xd I don't really get it yet enough