What happened?

I was testing working on screenshots for an upcoming What's New Tour and found a change (regression?) in the Articles TinyMCE editor window. If you Toggle Editor on a filled in article, the window shrinks from 1188px x 550px on my 16" MacBook Pro to 198px x 58px (instead of being 1188px x 550px).

I'm using Nightly Build 6.1ß3 from last built:

Version

6.1

Expected result

The TinyMCE HTML vs Source Code editor should be the same size.

Actual result

The TinyMCE HTML is the correct size 1188px x 550px on a 16" MacBook Pro.
The TinyMCE Source Code mode is 198px x 58px on a 16" MacBook Pro.

System Information

Joomla 6.1 ß3 nightly from Tuesday, 10 March 2026 00:52:01 UTC.
PHP 8.5.3, MariaDB: 10.11.14

Additional Comments

When comparing to Joomla 5.4.4-dev, the Toggle Editor Source code mode works perfectly fine...

When comparing the source code in Inspect Element, I see the following missing properties for the <textarea name="jform[articletext]" id="jform_articletext" cols="" rows="" style="width: 100%; height: 465px; margin-top: 0px; margin-bottom: 0px;" class="mce_editable joomla-editor-tinymce valid form-control-success" aria-hidden="true" aria-invalid="false">

{width: 100%;
height: 465px;
margin-top: 0px;
margin-bottom: 0px;
}

none of those 4 are in the Joomla 6.1ß3 nightly build.