Viewport at 1920x1080 show black band when displayed in exclusive fullscreen on 1920x1080 monitor

Godot Version

4.2.2

Question

Hello,

I encounter a problem with my futur little pixel art game.

Following this guide : Multiple resolutions — Godot Engine (stable) documentation in English

I set these parameter :
Stretch mode : viewport
Stretch aspect : keep
Stertch scale : integer

I choose a resolution of 1920x1080 for my viewport.
But when i played the game on a 1920x1080 monitor the game look like in 960x540 with big black band around. But when i played it in 3840x2160 the scalling work and i have the game in full screen without black band.

Is it normal ? Did I miss something ?
Based on my understanding with a viewport of 1920x1080 the game was design to be native in 1920x1080 and should not display black band on 1920x1080 monitor.

Here are some screenshot :
Configuration :

Played game on 1920x1080 monitor :

Played game on 3840x2160 monitor :