Search facets displays zero results when result set contains less than the per-page result count, and user is viewing page two or later of results.

[lukewhitmore]

To replicate:

• Using https://understandingpatientdata.org.uk
• Enter 'test' as search term.
• Open 2nd page of results.
• Select 'Information [2]' in facet block.

Actual:

• No results are shown.

Expected:

• Display of two results.