I can get an OTP and log in now.
The only difference is that you can now try and book 30 October as well as remaining times on 26 and 27.
Perhaps this is the new normal. They release dates 30 days ahead, first come, first served. Explains why no dates were available prior to 26 Oct, being 30 days from when the new system went online
Before there were two appointments available for each time slot, now appears to be only one. Not got that far though as no dates suit my needs