Nice to see you on here Roger, – for everyone else, we used to work together years ago – I’ve searched for just this problem and found your post.
I was getting the same issue and I think I’ve worked it out (I think).
If you manually rename a text layer’s Layer Name in the timeline (select the layer in the timeline, hit Enter, type the new layer name, then Enter again), it will remain that name even if you modify the text in the Comp. I’m guessing After Effects thinks that’s the name you want the layer to be, so it won’t change it.
If you duplicate that renamed text layer, it will become (for example) “Big Sale 2” and will remain that name if you modify the text in the Comp.
By clearing the Layer Name text in the timeline (select the layer in the timeline, hit Enter, hit Delete, then Enter again) you reset the Layer Name to mirror what is in the text layer in the Comp.
I think that’s what seems to happen anyway, hope that helps.
Thanks
Lee
Lee Harper
Animation Director
Gizmo Animation
http://www.gizmoanimation.co.uk