When using the Solr backend for collection generation, if the Solr "Results per page" and collection SP "Default collection objects per page" don't match, the collection pager isn't accurate.
The collection pager will always use the "Default collection objects per page" as the page size (limit) to calculate how many pages there are regardless of how many objects are actually displayed per page.
Steps to reproduce
Set collection "Display Generation" to Solr
Enable "Allow Solr result limit block to override collection limit" in collection SP
Set "Default collection objects per page" to 2 in collection SP
Set "Results per page" in Solr settings to 4
View a collection with more than 4 objects and use the pager to go to the last page.