I tried some cases, but there was no result

[gk966988]

I tried some cases, but there was no result
such as:

[Saeed-Biabani]

according to the mask generated by the model, I guess the surface of the table is mistaken for the surface of the paper. Because the surface of the table as white as paper. It is recommended that the background color be other than white. And also the paper should be completely in the frame

something like this: