Black border after clipping

[nabbe]

Hello and good day to all.
I have a problem with the cutout that I can't solve. After having made a cutout I drag the layer with the mask into another file. Most of the time, however, this layer has a black border along the outer edge of the file.
It is highlighted more if an external shadow is applied to the layer. This is very annoying because it is not always visible and many times it is present in the print.
the border is not always visible and becomes evident if I zoom out on the monitor.
I attach an example

I hope there is a solution.

thank you very much

 

[IamSam]

Hello and welcome to PSG.

This appears to be just a matter of a poor selection at the time the layer mask was created. What was your steps and tools you used to create the selection and the layer mask?
Did you add a layer style and a possible stroke to the layer?