Find likely causes of missing subject parts and decide when another source photo or manual mask is needed.
Compare the missing area with the source
The model estimates the visually prominent foreground. It does not know which parts you consider essential. A thin strap, a pale sleeve or a hand against a similar wall can be classified as background. First confirm that the detail really exists in the source and is not already outside the frame or hidden by another object.
Simplify the evidence
Try a source with clearer subject separation. If the item occupies only a tiny part of the photo, prepare a tighter crop in an editor while retaining the full outline. This gives the subject more room in the model's working representation. Do not assume that uploading a much larger file automatically solves the issue; the model still analyses a reduced representation.
For a backpack, the main body may survive while a loose black strap blends into a dark table. A new photograph with a lighter surface makes the strap easier to distinguish and gives you a more reliable editing starting point.
Do not hide a structural error
An outline can emphasize surviving pixels but cannot bring a missing strap back. Repeatedly processing the cutout also cannot restore removed information. Use a manual editor or change the source when the missing part affects recognition or product accuracy. Keep the original beside the result for the final check, especially when a smooth edge makes the mistake easy to overlook.