They've been messing about with the 'Relevant' sort order, there is another thread on this though the title of the thread is a touch ambiguous:
https://discussion.alamy.com/topic/17600-image-order-in-portfolio-randomly-re-organised/page/4/#comment-360435
It looks to me like you have just found another unwelcome consequence of this new algorithm, it is also the default which doesn't help matters. Nothing much back from Alamy about this.
Something I've just noticed, if I do a search for 'Audlem cheshire' I get 313 images, so just into 4 pages of results. If I change the sort order to 'Newest' I imagine that I get something closer to what you are expecting, still 313 images. If I select 'Oldest' as the sort order then suddenly I'm only getting 267 images.