1920 frame size to large for 1920 screen?

Hi everyone, I’ve searched but not found any answers to my question. I am a developper, my designer gave me a Figma file, design in 1920 px width, under my advice because it’s a base for me. My laptop fit to this size, however, in the view of Figma, the 100% frame is larger than my screen and it drives me mad. Now that the design look good, any sizes are wrong, police sizes are way to big. I don’t understand why a 1920 px width screen in Figma is’nt really 1920 px. In any other software, when I set smth at 1920 px it fit my screen at 100%.