FWIW...sounds like you have a process that is invoked by some other means than the normal service manager. Ex. Task Scheduler. If you set the process start to 'manual' (also sometimes called 'Demand') and it continues to restart, something else is restarting it. Other restart possibilities besides task scheduler -- a licensing daemon that launches when a program that uses it starts. An "assistant" service, that helps process something like a browser request -- like some sort of video viewer may be started to play some videos, or if you download a torrent (or magnet), those are usually handled by some sort of bit torrent compatible program -- but I'd think those would usually stay off until you downloaded another torrent file. If you download a zip file and choose to open it, 7z, or some similar util might open to open the file, or acrobat (or its viewer) might open to look at a pdf.
There are tons of helper processes to process various file types/requests. If you aren't using any of those,
then a first place to look might be the task scheduler.
A program 'Autoruns' from 'sysinternals via MS' can show you all the auto-started programs on your system
from https://docs.microsoft.com/en-us/sysint ... s/autoruns
. Also, it would help if you could tell us the name of the service...maybe one of us has seen this problem and dealt with it...