A DESCRIPTION OF THE PROBLEM :
This is similar to issue JDK-8229394 but with a few key differences.
When you start a JavaFX application remotely via Remote Desktop and then you disconnect (not logoff) the remote session while the app is still running and then reconnecting, the running app will not be able to repaint.
The key difference from JDK-8229394 is: That issue mentions the app was started locally and then was accessed remotely, in this case, the app was started via remote session.
The other key difference is: This seems to only be an issue when the remote machine is running Windows 10.
I've also tested this against Windows 8.1, Windows Server 2012, and Windows Server 2016 and it works fine.
It is ONLY an issue with Windows 10.
CUSTOMER SUBMITTED WORKAROUND :
There is no workaround aside from restarting the app.
FREQUENCY : always