messageParent of Outlook AddIn Api not working anymore

Description of the issue:
The messageParent method of the Office AddIn Api does no longer work in Brave. (It worked some weeks ago). No event is raised on the parent side. I also see no error in the console.

Exact URL of the website in question:
The Website is only internal available

Did the issue present with default Shields settings? (yes/no)

Does the site function as expected when Shields are turned off?

Is there a specific Shields configuration that causes the site to break? If so, tell us that configuration. (yes/no):

Does the site work as expected when using Chrome?
It worked with edge (old one). I need to install chrome, I’ll post an update later.

Brave version (check About Brave):
Version 1.10.97 Chromium: 83.0.4103.116 (Official Build) (64-bit)

Installed Chrome. Also not working in Chrome :frowning: