This "settings, appliactions manager, all, download manager, stop, clear data" doesn't work for me on my Galaxy Note 8. Maybe I should add a picture. I rebooted several times. It drains my battery very quick. In no time I'm from 100% down to 34%.
Life is strange sometimes. My problem is solved. I never knew how to see the notification area, but I just found out. Touch the arrows and "tear/scroll/wipe them down". Notification area will appear. There is the solution. I had 2 ongoing downloads and I wiped them out. That's it. As simple as that. Hope this can help many people.