RTE: Anchor gets stripped in UI when re-opening link

[Frost117]

Which Umbraco version are you using? (Please write the exact version, example: 10.1.0)

13.5.2

Bug summary

When you add a # to a link in a RTE, you'll see that the link itself is being rendered with the anchor point like so:

Front end:

After clicking on link:

It is only when you re-open the link in the RTE that the # is gone from the Anchor / querystring box:

Specifics

No response

Steps to reproduce

1. Create 2 doctypes -> Home Page and a Sub Page

2. In Home Page, add the datatype Richtext Editor.

3. In Home Page, under permission allow as root and add Sub Page as a child.

4. Create 2 Content nodes -> Home Node and a Sub Node.

5. In the Home Node, in the RTE field, write some dummy text.

6. In the RTE on the Home node, add a link to the Sub Node and in the Anchor / querystring box, add an anchor point like so:
   

7. Save the content and view the page.

8. After verifying the link on the front-end has an anchor point, go back to the backoffice and open the Home node.

9. Click on the link and open the dialog box to see the following:
   

Expected result / actual result

When I save the anchor point with a # then I expect to see that when I open up the dialog box again

---

This item has been added to our backlog AB#46177

[iOvergaard]

This has been fixed in V15 with #17288, but I wonder if we can cherry-pick that back to V13. I will make sure it gets included in one of the upcoming development sprints.