Hello Joachim,
When you are sharing a CODAP document, you can think of the original document as the master from which all shared copies will derive. It’s the document that generates the unique ID for shared copies. It’s usually a good idea to keep this master document somewhere where you’ll be able to find it again.
If you modify the master document, you can Update shared view either in the “hamburger” menu or in the Get link to shared view dialog box. Updating will mean that the next time someone uses the shared link they will get a document with your modifications.
I think that in your situation you are modifying a shared view (a copy) of your original document. It’s now an independent CODAP document that has lost all connection to the original “master” document. Sharing this copy will start the process all over again. Changes to this copy followed by an update will not affect shared views of the original master document.
The only way to affect the shared views of your original document is to go back to that original, change it, and update the shared view from there.
You ask if it is possible to stop sharing a document. Yes! In your original document, go to the Get link to shared view dialog box where you will find a Stop sharing link in the upper-right of the dialog box.
I know this is kind of tricky, but it does work well once you get the idea that there is a master document that rules them all.
Hope this helps,
Bill
p.s. And I just saw Dan’s much more succinct reply to your question. Between the two of us I think we’ve covered it all.