Thanks Andy.
Yesterday I had a result with someone @ BT and they blocked the first line and had the features passed to line2 instead, to see if this showed a fault with Line1 or the service. And it indeed followed to Line2 😞
I have requested they remove the FeatureLine service completely which should be completed by tomorrow to see if this fixes the issues.
I will know more tomorrow.
Thanks again.
PaulG.