Tacx software freezes -- any suggestions?

I have a FluxS trainer working with the Tacx software. We start biking and the film plays but the stats (rpm, distance, time, etc.) don't move after the first few seconds. Or sometimes it will update again 15 minutes later. Then sometimes the film freezes as well. Any ideas on how to get this app to work more smoothly? (We're just on the free premium trial, so not super familiar with this.)