When citing a page, the Biblatex manual puts a tilde between "p."/"page" and the number:
Why? I actually have never really googled for this and now that I have, I am unable to find any good results or think of one.
I recall that I used
a couple of times and I didn't have any problems with the space disappearing or anything. Then I converted back to the tilde method just for the sake of it but did not inquire about it.