Gotcha. Sorry Greg, I think I was confused.
The parallel set up is primarily for stereo input, such as a keyboard. If you have it on a mono in/stereo out track, it sends your guitar to both amp/cabs. Check the two amps/cabs are panned L/R in the mixer, but they have almost identical settings so you're probably not 'hearing stereo', just dual mono. Easiest way to tell is by dropping a delay stomp in just before one of the amps and you'll then hear the difference.
If, when you do this, you can still hear the delay only down the middle rather than to one side then there might be something to do with Cubase setup that I don't know about, in which case if no one else chimes in here with advice or a solution the best thing to do is check the FAQs, via
https://www.ikmultimedia.com/contact-su ... ck=QUICKSWIf these do not resolve the issue, there is a link to the Technical Support form at the top of the Search FAQs page, for direct help from Official IK Support. They endeavour to reply within 2 working days, but obviously considering the current situation things may take longer than usual.
And, to help others who run into a similar problem, please let us know what you did to resolve the issues, but without directly quoting any correspondence from official support.