WebView2 fails to load in Office Add-ins, with different monitor scaling settings

Description
An Office Add-in with WebView2 rendering in a custom task pane stops working on displays with different scaling than the main display.

Added solution where problem can be replicated:
WordWebView2AddIn.zip

Version
SDK: 1.0.664.37
Runtime: WebView2 Runtime 87.0.664.75
Framework: WinForms
OS: Win10 1909, Word 2101 (Build 13628.20118)

Repro Steps

1. Download solution provided in the bug
2. Assuming you have at least two displays, go to Display Settings and change the scale of items on one of your displays so that it differs from your main display (e.g. set the main display to 100%, secondary display to 125%)
3. Make sure the Start-up screen in Word is disabled
4. Start Word from the add-in solution in the secondary display
5. Check if page is rendered and word is not frozen

Screenshots
Expected and what is displayed when opening Word on main screen:

Displayed when opening on a secondary screen (the application is frozen in this case) and also when start-up is enabled

Additional context
Also replicable in the latest pre-release version.

When having the startup screen (also called backstage) enabled, the Webview2 control does not render at all, despite the navigation happening in the background. That was verified only through debugging.

AB#31424281