A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data
Dear Craig Rothchild,
Good day.
Thanks for posting in Microsoft Community.
AutoComplete algorithm for dropdown list matches the string you type in the dropdown list cell with words from items in the dropdown list and then shows only the matching list items. AutoComplete for Data Validation drop-down list is available in version 2112, build 16.0.14818.10000 or later.
If you cannot use this feature, please check if there are any updates of Office. You can update your Office applications in the following ways: Open Excel -> File -> Account ->Update Options ->Update Now.
For details, please refer to:Speed up data entry and validation with AutoComplete for dropdown lists in Excel for Windows - Microsoft Tech Community
Sincerely,
Tin | Microsoft Community Moderator