I tried both methods and the manual sync to the head unit worked!!! Thanks for your help 
So the workout is appearing on my headset and in the element phone App. I was hoping I could follow my workout on my phone, as it’s obviously bigger than my headset. But the workout appearing in the phone app is static. Is there a way of changing that?
I don’t think so. The automatic workout screen in the elemnt is decent given the constraints, but nothing compared to the live UI on a phone or tablet with your trainer. You can peek at the workout W-profile by pressing the middle <<>> button but I think that pauses the workout timer so you can’t do the interval with it up.
If you want to use your phone, have you tried not marking the workout outdoors and just running TR on the phone outside? Just pair your power source and pretend you’re inside. It’ll be like a slope-mode workout on an indoor smart trainer.
Don’t tell Chad, but I don’t do structure outside at the moment. I’m really focusing on flow and MTB skills.
At the moment I have an old watt bike trainer, not smart bike. I’m planning on buying the new Stages indoor smart bike as soon as it’s available. I thought I would work out some of the connectivity issues I have before then.
I think I will have to work out the set up all over again when I get the Stages bike, but I’m a bit more confident about working through the issues now, before I spend nearly 3k !
Thanks @gcarver
So when I get the Stages indoor trainer I can just link it directly to TR app and don’t need to use the Element/ wahoo app right?
Correct.