Moving text via block/selection

I originally posted this in another section, but I thought the problem cleared itself up. It didn’t. In most word processors and writing software that I’ve used, one can move text around the page by blocking or selecting the text and then using the cursor to drop it to a new location. I can do this with new text, that is, a section I am writing. However, I can’t do this if the text I’ve been working on has been imported or cut and pasted into the section. When I try to move a portion of the imported or cut/paste section, I get a circle with a line in it, commonly refereed to as the “no” symbol. It is as though that text is protected. I can cut the section and paste it to a new location, but not select/block drag and drop. (I hope I’m being clear in my description.)

While cutting and pasting the imported section is a work-around, I would be smoother to be able to drag and drop the sections I wish to relocate. Any insights?