ActionButton not working with Microsoft Defender for Cloud Apps (formerly MCAS) active

[patricksengeis]

When having the Microsoft Defender active the URL of the Dynamics changes to this:
https://xxxxxx.crm4.dynamics.com.mcas.ms

That seems to break the check if being in Design-Mode or directly in an Form for the ActionButton:
if (location.ancestorOrigins[0] === "https://make.powerapps.com") { this.isDesignMode = true; }

I get the following exception in console (see screenshot).

After changing the code to get the hostname instead of checking for ancestorOrigins, its working again:
if (location.hostname === "make.powerapps.com") { this.isDesignMode = true; }