When pasting in a copied text from another website the resulting code contains unwanted HTML-Code.

In the video it can be seen. https://www.screenpresso.com/=mCK7d

1) I open an article in the editor.
2) I mark some text on another website
3) I mark the text in my website, with should be pasted over.
4) I paste the text from the clipbord via the paste-popup.
5) When switching to the editors code-tab, there is a lot of formated code, that is unwanted.
6) When cleaning up the text by the cleanup-icon in the editors edit-tab, most of the unwanted code is away.
But there are still some entries: <!--StartFragment--> ....... <!--EndFragment-->

That entries must also been deleted.

! When pasting with cntl-v or win-v the fragment code does not exist.