Well, KB4517389 on 1903 is a bomb for me. First time I've had a noticeable issue with a Windows update. Blew out the ability to type in the Search box in the tasbar or to type to search in the start menu. Uninstall fixed it for now. Was hoping I wouldn't have to do that since I suspect a September update has been causing another issue on my new build. Went from being totally stable when first built in August to randomly every day to couple days I'll go to my desk and it's rebooted from a bugcheck where it can't even save the memory dump. Although that could be a buggy X570 board BIOS update as well.