vscode: Windows: integration tests often fail with `CodeWindow: failed to load workbench window (reason: , code: -3)`

Lately I often see our Windows integration tests fail (e.g. https://dev.azure.com/monacotools/Monaco/_build/results?buildId=122214&view=logs&j=672276a2-8d3a-5fab-615d-090c51352f92&t=354d3e13-3534-5793-0b68-b00f8c1d36f3&l=1052):

[main 2021-06-08T08:51:23.804Z] CodeWindow: failed to load workbench window (reason: <unknown>, code: -3)
Exec: 
At D:\a\1\s\build\azure-pipelines\win32\exec.ps1:22 char:3
+         throw ("Exec: " + $errorMessage)
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (Exec: :String) [], RuntimeException
    + FullyQualifiedErrorId : Exec:

With the new support of Electron 12 to indicate the exit code, I added this and it seems to be -3 which somewhat looks like the requests are aborted, similar to our handling here:

https://github.com/microsoft/vscode/blob/100a70731dbf4b811744b5153e45ebc11c37b93d/src/vs/platform/protocol/electron-main/protocolMainService.ts#L97-L97

Curious though what the origin of this issue could be. Is there a way to figure out if we are triggering this from our protocol handler?