Thank you for posting! I am sorry things have stopped working as expected while using your Plugable UD-3900 docking station and I would be happy to help.
Based on your description of the behavior, our first step is to get some additional information.
If you would, please keep the dock connected to your system and the displays connected to the dock (even though not working as expected) and send the output of our diagnostic utility PlugDebug --> http://plugable.com/support/plugdebug to us directly via firstname.lastname@example.org with ‘For ticket #310729’ in the subject line. This will allow us to match things up and examine some log files from your system, which will help us determine the next steps.
** Please also include the Amazon Order ID number for the UD-3900 purchase within your direct email, it is required to confirm warranty status **
** Please do NOT post the PlugDebug file or the Amazon Order ID number here in our public forum **
Apologies again for the frustration, and thank you for giving us the chance to help!