An easy idea is to run them in GUI Commandline. The other issue has no past forum or Issues reports, meaning it may be harder to resolve. You can start by looking in About → System info to determine the BaseVersionName and ServerVersionName. What is C:\Program Files\Duplicati 2\changelog.txt start?
If you like, you can also turn on Task Manager → Details → Image path name to see what Service runs, however you will probably see two Duplicati.WindowsService.exe processes and a Duplicati.Server.exe which may be running some combination of Duplicati versions, and as a guess maybe that’s relevant…
If you find that the Program Files version is not being used by the service, but another is, you could try to run from whatever the Server is running, if you absolutely have to use true CLI instead of GUI somehow.