It seems that only Alishka has had the same problem, i.e., that clicking on the calendar doesn't bring up any more dates for us. It simply shows the message 'we have no more slots available' ! The same happens if I tap the 'next 3 days' button.
I have found no way of getting around this, and have even tried logging in on other devices to see if that made a difference, but it didn't.
Megs36 The reason I asked about shielding is because my mum rang customer services yesterday to ask about this, and was led to believe that it would make a difference to how many available slots she might see (she wasn't on their list but they are now going to add her), but unless we can see slots beyond the next three days, I don't see how it can make the slightest difference!
The reason I asked when people had registered with them for online shopping was in case there had been a glitch in the system at one time which might have led to this problem for anyone signing up right then - though that's a long shot, as I doubt the problem would have persisted!