Tested duplicati-2.0.9.101_canary_2024-06-27-win-x64-gui.msi by clicking in Explorer.
Got an Apps item for Duplicati (not Duplicati 2. I’m not sure what’s expected now.
Got about 87 missing files compared with the content of the .zip file. Some evidence:
C:\Program Files\Duplicati 2>dir Duplicati.GUI.TrayIcon*
06/27/2024 11:43 AM 202,880 Duplicati.GUI.TrayIcon.deps.json
06/27/2024 11:44 AM 107,672 Duplicati.GUI.TrayIcon.dll
06/27/2024 11:44 AM 333,976 Duplicati.GUI.TrayIcon.Implementation.dll
06/27/2024 11:43 AM 445 Duplicati.GUI.TrayIcon.runtimeconfig.json
C:\Program Files\Duplicati 2>dir *.exe
05/17/2024 05:38 PM 65,872 createdump.exe
06/27/2024 11:44 AM 160,408 Duplicati.CommandLine.AutoUpdater.exe
06/27/2024 11:44 AM 160,408 Duplicati.CommandLine.ConfigurationImporter.Implementation.exe
06/27/2024 11:44 AM 160,408 Duplicati.CommandLine.SharpAESCrypt.exe
06/27/2024 11:44 AM 160,408 Duplicati.CommandLine.Snapshots.exe
C:\Program Files\Duplicati 2>dir Duplicati.Library.*.dll
06/27/2024 11:44 AM 54,936 Duplicati.Library.AutoUpdater.dll
06/27/2024 11:44 AM 34,456 Duplicati.Library.Backend.AliyunOSS.dll
06/27/2024 11:44 AM 32,920 Duplicati.Library.Backend.Idrivee2.dll
06/27/2024 11:44 AM 43,160 Duplicati.Library.Backend.Storj.dll
06/27/2024 11:45 AM 29,336 Duplicati.Library.Backends.dll
06/27/2024 11:44 AM 58,008 Duplicati.Library.Common.dll
06/27/2024 11:45 AM 43,160 Duplicati.Library.Encryption.dll
06/27/2024 11:44 AM 283,800 Duplicati.Library.RestAPI.dll
06/27/2024 11:44 AM 82,072 Duplicati.Library.Snapshots.dll
I did not uninstall the previous Duplicati before the install. I don’t know if that might matter.
EDIT 1:
Clicked the .msi in Explorer again, got some choices, chose Repair. That fixed things up.
There are minimal differences compared to .zip. I still have two old service installer files.
package_id_type.txt files are different, but that seems OK. This one says win-x64-gui.msi
EDIT 2:
TrayIcon comes up now, though it didn’t seem to get a new tab in my open Edge browser.
I kind of expected it to be on port 8400 (third Duplicati at the same time). It was, and said:

which is probably just a leftover notification in the server database, and a clue to prior use.
I wonder if these old notifications should be purged, as I think the updater is now different?