Hellgate and UltraWide screens

I’m using a 3440×1440 resolution as native for window (“21:9”)
The game recognise it, but the aspect ratio is not good, he stretch from the nearest 16:9
If I switch to a 16:9 resolution, 2560x1440, the game use black bar left and right (like any other game) but, there is a side effect; the game modify the windows desktop resolution if I alt tab.
If I ask to play in “window” the game lock the window in 0,0, so I have my desktop on the right side…
Is there a way to fix the way the game configure resolution, it seems so 2007 ^^

In fact I can accommodate to play with the full screen mode, but there is, again, a side effect.

The mouse doesn’t work very good, if I move the mouse and clic, I have to clic twice.
If I play in windowed mode the bug doesn’t exist.

Example I want to mode an item in the inventory. I clic on the item, start to drag.
I move the item, I release or clic when I want to put the item, nothing, I clic another time, it works.
When dismantling items, a right clic, move the mouse, release, nothing, clic again, it works.
The problem exist also while fighting. If I clic while not moving the mouse, my character will attack in loop even if I released the button. I need to move the mouse to reinit that (example with a sniper weapon)

This is very strange, and It’s related to the resolution. I played on a real 16:9 monitor and don’t have any problem.

i have the mouse problem too^^