If the saved search does not show the correct quantity in the reminder's portlet, it may have something to do with the Saved Search settings like if the Available for Reminders and Public is enabled. Summary types can also cause issues when showing it via reminder's portlet.
2. Available for Reminders checkbox must be enabled.
3. Under Results subtab > Columns sub tab, check if fields has Summary Types.
Name | Summary Type = Group
Number | Summary Type = Group
Amount | Summary Type = Sum
Some summary types does not work well when the saved search is use in the reminder portlet. Users may look and vote for Enhancement 162614 : “Reminders Portlet: Provide ability to acknowledge the Summary Type feature of Searches”.