@MichaelVolz
My script wouldn't run via Windows Task Scheduler with any of the above suggestions, until I tried running it from Pro's scheduler. I loosely followed this Pro help page: https://pro.arcgis.com/en/pro-app/latest/help/analysis/geoprocessing/basics/schedule-geoprocessing-t...
Basically, I saved my stand-alone script as a script tool with no parameters. Before you hit Run, set up the schedule. I added a bunch of arcpy.AddMessage() print statements so I could see how it was progressing.
As MichaelTorbett said, Pro actually uses Windows Task Scheduler to run the geoprocessing tool. In the Task Scheduler, under the Actions tab, it used the pythonw.exe file as the Program/script and the argument was stuffed away here: "C:\Users\me\AppData\Local\ESRI\ArcGISPro\Geoprocessing\ScheduledTools\WasteRecyclingReport_02012022_0325PM\task.py"