CT10 Sensors all show as unassigned when starting a round

I find that I have to reassign every sensor before starting a round.

So I get to course, start the golf app and it immediately says ‘one or more sensors are unassigned’. 
Looking through the list it is all of them, so I have to either remove and readd each one or reassign to the club. I’ve tried both methods and also removing them all and re-adding at home beforehand but get the same. 

I got the sensors brand new 2 months ago.

I see forum posts going back 3 years for this problem for Approach watches. 

Is there likely to be a solution ever?