This is due to the fact that a display with this size has pixels that are not square, but elongated horizontally. Such problems are observed on all such displays. The size of the visible area is 222.7×125.3 mm, and the resolution is 1024×600 pixels. So the size of each pixel is 0.2175×0.2088 mm. So if a circle is drawn with a size of 440×440 pixels, then physically on the display its width will be 440*0.2175=95.7 mm, and its height will be 440*0.2088=91.872 mm. This is exactly what you see in your photos.
In the case of your own drawings, you just need to take this into account and draw them a little compressed horizontally. To be precise, their width should be reduced by a factor of 1.042 (0.2175/0.2088=1.0412).
In the case of ready-made widgets, such as Progress Circle, I think that nothing can be done. Just write to support about it and ask them to make the possibility of separate scaling along the axes.