Not really, but ages ago when I had problems with a Tacx trainer (not a Flux) Tacx had a diagnostic app for the phone and it was really helpful.
Now, I think they've withdrawn that useful app and rolled the functionality into the training app. So if you have a phone handy it might be worth using that (it will use bluetooth) to connect to the trainer and see if you can learn anything.
Sorry if that's not much help, but it's an idea for an approach.
Another (even les useful) suggestion is to make sure that there are no other ANT+ receivers (like a Garmin or Wahoo GPS) around and switched on. The reason I suggest this is that when I had bluetooth connection problems between my Flux and my PC I found that switching bluetooth off on my phone fixed it. (Or at least, problem went away when I did this) I think the trainer was getting confused about what to connect to.