Thank for the replies - I think this is now resolved.
I think the problem is my misunderstanding of the block definitions in the default templates. I have been using iso_en_a4_metric_landscape_aec.dxf and assumed that the title block used dependent attributes, but it appears that these are just normal block text. I’ve set up a new block myself and defined a couple of Block Attributes, and that all works as expected.
Husky, It looks like your post here contains the templates I’m looking for: Imperial (US) drawing sheet templates, ANSI A-E - thanks for these.