Blinking TinyMCE editor in OPE

Description

Steps to reproduce

1. On Alloy Plan, in the Main body property, add long HTML.
2. Simplify the Product page view:

@using AlloyTemplates
@model PageViewModel<ProductPage>
 
@{ Layout = null; }
 
<div class="row">
    <div class="span8 clearfix" @Html.EditAttributes(x => x.CurrentPage.MainBody)>
        @Html.DisplayFor(m => m.CurrentPage.MainBody)
    </div>
</div>
 
<div style="display: none;">
    @Html.PropertyFor(x => x.CurrentPage.RelatedContentArea)
</div>

3. Run the site.
4. Scroll somewhere in the middle of the HTML editor.
5. Click to start editing.

Notice that the editor is blinking.