When I look at our rapidboard with our "Next Iteration" quickfilter set, I only see four issues:

https://ecosystem.atlassian.net/secure/RapidBoard.jspa?rapidView=23&view=planning&quickFilter=71

However, the equivalent query in JIRA (actually, a more restrictive query that only shows open issues) shows at least 80 results:

https://ecosystem.atlassian.net/secure/IssueNavigator.jspa?reset=true&jqlQuery=project+in+%28UPM%2C+AMKT%29+AND+fixVersion+%3D+%22Backlog+-+Next%22+AND+issuetype+%21%3D+Approval+AND+issuetype+%21%3D+%22Approval+Subtask%22+AND+%28component+%21%3D+Approvals+OR+component+%3D+EMPTY%29+AND+status+%3D+Open+ORDER+BY+Rank+ASC

An exemplar issue is https://ecosystem.atlassian.net/browse/AMKT-2797

Re-indexing JIRA has no effect.