Hi Doug, hope you are well !!
So, if you upload to LoTW and you get the notepad screen, then you have LOGic set to review the QSO's to be uploaded before it actually does. That "review" screen only serves to allow you to review the upload and edit it if needed before it actually uploads. If you close that screen or x-out of it the upload process continues, it doesnt stop it. The next screen that should pop-up is I believe a TQSL related window, its looking for a date range for the upload should you need to specify one, but it has a radio button "cancel", maybe try clicking on the "cancel" button and see if that stops the upload. If I remember correctly (hihi) I think it exits the upload process, not 100% sure but try that next time and see.
Brad, K8ZM