I use AppleScriptTask to call my Apple scripts in Word. In addition to Automation, I'd check SystemPreferences/Security&Privacy/FullDiskAccess to see if Excel is listed but greyed-out. If so, click it to activate Excel to have Full Disk Access.

Also, check that the Apple scripts are in the User's ~/Library/Application Scripts/com.microsoft.Excel bundle where Excel will look for the scripts by default.