Prerequisites
ImageSharp version
3.1.0
Other ImageSharp packages and versions
3.0.1
Environment (Operating system, version and so on)
Windows 11
.NET Framework version
.NET 6
Description
On some picture, ImageSharp will add a gray rectangle at the bottom right,
Original: 
Final: 
Steps to Reproduce
Download sample projet c#
Replace fb.jpg with the original picture:

try it with version 3.0.1, (no gray square)
erease debug + obj and install the latest version 3.1.2 and execute, (gray square)
Images
No response