It sounds like your script might be acting up on Windows 11 compared to Windows 8. First, double-check that the script is only turning off the display and not triggering sleep. If that’s not the issue, try creating a new power plan in Control Panel > Power Options and set it to your preferred settings. You could also run the Power Troubleshooter by going to Settings > System > Troubleshoot > Other troubleshooters to see if it finds any problems. These steps might fix the issue without needing to disable Modern Standby and interrupt your download.