Mine is set to Manual and when I've checked its Properties, its Startup type is greyed out, but I have Norton Security installed on mine which would have disabled it anyway.
What did the tech shop do to resolve it ?
WR resets the Services to default, but there doesn't appear to be an answer as to why it's frozen, unless as it is the only AV program you have then perhaps Windows had decreed that you cannot stop or change its start up.
I think you may have perform a repair install to resolve this if that isn't the case, although installing a 3rd party AV program may change its status as when one is installed, that would disable it.
For the repair install, if you don't have a Win 10 install disk or USB then you can create one by using the Download tool now button in
https://www.microsoft.com/en-gb/software-download/windows10 and read the instructions for use the tool to create installation media.
When done, open Windows Explorer, click on This PC - stick the disk in and hit the Setup.exe
This won't affect your personal files or any programs you have installed.