Cannot edit right side of HTML Editor Extender

[Nmazer]

The AJAX Control Toolkit <VERSION>

Version 20.1

The installation method

• [ x] Installer
• NuGet package
• A custom build from the source code

Minimal steps to reproduce the bug

Create a VB.net web form and place an AJAX HTML editor extender with a width of 1045px and height of 480px. Copy and paste several lines of text. Drag the cursor from left to right. On the jest side the cursor is an edit icon. On the right iris an arrow. The left can be edited, the right side cannot.

Actual result

See above

Expected result

Both sides should be able to be edited.

Browser(s) used

A site deployment method

• VS development web-server,
• [x ] IIS

this is in VS 2019 Webforms project.