When you upgraded, it sounds like it switched to operating as a regular user process instead of service. Remove duplicati from your startup folder and exit any tray icon that may be running. Then, after confirming there are no Duplicati processes in Task Manager, enable and start the Service. It should bind to port 8200 and you should be able to see your jobs again.
In the future, when you are going to do an upgrade make sure to:
- Stop the Service
- Run the Installer
- During install - disable the option for adding Duplicati to startup
- At end of install - uncheck the option to launch Duplicati
- After install has finished, Start the Service