There was a hotfix released for a performance issue with the Arrival Overview form. However some people may still experience performance issues when going to Inventory Management > Periodic > Arrival Overview and changing the setup name to return order. This has been seen when you have a lot of backorders. To resolve this you can add the following line to the buildOverviewQueryReturnOrder method of the WmsArrivalOverviewGeneration class.
dsSalesLine.addRange(fieldnum(SalesLine, SalesStatus)).value(SysQuery::value(SalesStatus::Backorder));
Depending on your data you may need to add additional filters or indexes to assist in optimal performance on this form.