Quote:However, when I select the area with rectangle selection tool and use "cut" it cuts the entire layer.
Is there a simple fix?
hmmm.. new-user error
Once you make a selection, better to fix it, various ways but hit the enter key is one. That will give the crawling-ants border.
Now you need to do something with that area, one is cut Edit -> Cut but you can also copy all depends on what is required.
Once the selection is cut (or copied). close the selection Select -> None
Then again, depends what is required but Edit -> Paste puts the copied pixels back as a Floating Selection (Pasted Layer) which often baffles new users.
Easy to work with that, click and drag to where you want it and then fix in position using Layer -> Anchor Layer
30 second animation of that sequence. https://i.imgur.com/1d9mTqr.mp4