ADDITIONAL SYSTEM INFORMATION :
MS Windows 10

java version "1.8.0_221"
Java(TM) SE Runtime Environment (build 1.8.0_221-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.221-b11, mixed mode)

A DESCRIPTION OF THE PROBLEM :
I am deploying a Java FX WebView app using Web Start.
And I am having trouble authenticating with Google 2 Factor Authentication enabled.
However, It does work correctly for regular authentication (username & password only).
With 2FA: Google sends me the Yes/No option to my phone, but once I click yes, the webview doesn't respond.
Now, 2FA in the webview does work when I run the jar locally. It only fails when loaded via Web Start.
The Web Start URL is:
http://aubreigo.info/java/FX-People.jnlp
And the Jar file is located:
http://aubreigo.info/jav/FX-People.jar

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Launch the jnlp file. The webview will open for login to Google.
Try to login with a Google account ( 2FA enabled ).
When you click "yes" on your phone, the app fails to login.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
It should accept the phone verification.
And the app should successfully authenticate with Google.
Then the app will indicate that the login has succeeded.
ACTUAL -
The app fails to authenticate.

CUSTOMER SUBMITTED WORKAROUND :
Run the jar file locally. It only fails via WebStart

FREQUENCY : always