Searching for a first name with either a last name or first name alone still works, eg. searching for Jo* still brings up a range of first names - John, Joseph etc
But searching for Atkin* (looking for Atkin, Atkins, Atkinson) isn't working it only brings up Atkin surnames.
When I first asked the question, I noticed there were several questions that were similar, so the problem of the truncation not working on the Surname field seems to crop up from time to time. I only noticed it not working yesterday.