Hi, let me help you.
Check if your GPU resolution settings are the same as the Windows Resolution settings.
Right-click an empty area of the desktop, choose Display settings, and scroll to Display resolution. Note the value shown there, and the refresh rate under Advanced display settings if you want to compare that too.
Then check the GPU side. For NVIDIA, right-click the desktop, open NVIDIA Control Panel, and go to Display > Change resolution. For AMD, right-click the desktop, open AMD Software: Adrenalin Edition, and look under Settings > Display. For Intel, open Intel Graphics Command Center and go to Display > General, or right-click the desktop and choose Intel Graphics Settings. In each case, look at the resolution and refresh rate listed for your active monitor and compare them to what Windows shows.