If there is ever a time where the Cylance service has not started after installation, you can open the Terminal in MacOS and run the following command:
Start Cylance Service
sudo launchctl load /Library/launchdaemons/com.cylance.agent_service.plist
Stop Cylance Service
sudo launchctl unload /Library/launchdaemons/com.cylance.agent_service.plist
Note: You should use the autocomplete when typing the directory just to make sure there are no spelling errors in your command and this can be done by hitting the Tab key on your keyboard.