The pagination links are built from the $PAGE->url which does not include a logstore parameter. If a site has been upgraded from the legacy logstore only the first page of logs are returned without modifying the URL manually.

Steps to replicate:
1. View the report/log/user.php (can be accessed from user profile > activity reports > all logs) activity log for a user that has activities in both logstore_standard and a non-standard logstore (e.g. logstore_legacy), where the logs span multiple pages
2. Change the dropdown to the alternate logstore.
3. Select 'Page 2'.
4. Error 'Nothing to display'