Welcome to the forum, Jared.
Creo is very dependent on the graphics driver and as such, it could well be that activating the second screen may have changed something. However, rebooting is not one of the habits of Creo. It normally just hard crashes without affecting Windows.
You might want to get yourself back to where Creo worked with the single screen. Creo has a requirement of having at least 1024 vertical lines IIRC. Not sure if this can cause conflicts this extreme.
You could try changing the driver setting to "graphics win32_gdi" in config,.pro to see if this helps.
It may also be that there are issues with displaylink and when the primary monitor turns off, Windows thinks you went into sleep mode, or somesuch nonsense. I've always found it frustrating to get these tools working reliably.
If you still have maintenance, you could submit a support case. If this is an academic version, you can also log a support case here http://www.ptc.com/communities/academic-program/technical-support