Additional div defined in theme HTML is stripped out only when using 'Log in as'

Initial setup:

1. Enrol a test student in a course

2. Log in with admin account and add the following to Raw SCSS in site/admin/settings.php?section=themesettingboost>Advanced settings:

#redtext {text-align: center; color: #ff0000;}

3. Access test course and edit first topic section.

4. Expand editor and enable HTML entry mode. Paste in the following HTML then save

<div id="redtext">
<p>This text is red and centre-aligned</p>
</div>

Scenario 1 - Admin view:
1. View the section on the course page from initial setup

Observed behaviour: Text displays centred and red

Scenario 2 - Student account view:
1. Open a private browsing window and log into the site using username/password of the test student enrolled in the course
2. View the section on the course page

Observed behaviour: Text displays centred and red

Scenario 3 - 'Log in as' Student account view:
1. Logged into the admin account, navigate to the course users list
2. Click on the test student's name to go their profile
3. Click 'Log in as'

Observed behaviour: Text does not have the additional formatting. Inspecting element shows the div id attribute stripped out:

<div>
<p>This text is red and centre-aligned</p>
</div>

Expected behaviour: Text displays centred and red i.e. consistently with other views.