Line End Key goes all the way to right margin

When I hit the “End” key on my keyboard, meaning the key that makes the cursor go to the end of the line of text that it is on, it actually sends the cursor all the way to the right margin of the page, way past the end of the line. Is this a keyboard malfunction, or a Scrivener setting that I can change? Thanks!

Usually the text goes to the the edge of the editor window, minus the margins set in Tools>Options/Editor. So, if there is space there for the cursor to jump into you may have done something else to reduce the line length. Can you move the cursor to the same place with the arrow keys?

Yes, I can get it there with arrows.

That maybe implies there are some text characters there - spaces or tabs? Can you Show Invisibles and spot anything? (View ▸ Text Editing ▸ Show Invisibles)