java-cef | A simple framework | Plugin library

I recently integrated the Java Chromium Embedded Framework (https://github.com/chromiumembedded/java-cef) in a Netbeans (RCP) Application Project (Java: JDK11).

The Browser Window is shown in a Netbeans TopComponent and generally works just fine.

However I have several rather small, but nasty bugs that I noticed which are always following the same pattern: Whatever code I execute that concerns the jcef browser always only works when I execute it a second time and is all but ignored the first time around. However there are no error messages or logs or any thing like that and the code seems to be executed when I go through it with the debugging tool.

Three examples:

1. Implementing a return button:
   This just checks whether the CefBrowser instance returns true for browser.canGoBack(). If it returns true a button is activated.
   The value starts correctly at false, but it returns true just after the second change of url.(Should obviously happen after the first)
   From there on out it works just fine....Unless you go back (with the return button) to the home page. It should then obviously return false again - Which it doesn't.
   Calling a different URL again returns false for canGoBack() (which should then obviously be true) and only returns true after the second URL change again.
   So the return from canGoBack always shows the return it should have shown from its previous execution, as if lagging behind one time.
2. Implementing a "go to" function:
   This function just takes you to a specified other website than the home page. Again works fine from the 2nd time onwards, but the first time the code is simply ignored. (although I confirmed via Debugger that the code is executed without errors even the first time around)
3. Implementing a login dialog:
   If the browser notices that authentication is required, this opens up a dialog where the user can enter BASIC credentials.
   And again the dialog gets opened, the credentials are returned correctly (confirmed via Log), are handed over to the appropriate function and it works for the second try but not the first. (credentials were identical)
   Indeed I confirmed via Wireshark, that the first time that callback.Continue(ad.getUsername(), ad.getPassword()); is executed, nothing at all is actually send to the server...

Code for the third example: