Uninstaller quits immediately on Windows

Hi.

I've build an installer for my Qt application using Qt IFW 4.7. The installer is also signed.

Installing works well. However when uninstalling on Windows 11, the uninstaller quits instantly, not uninstalling the software.

How to reproduce:

1. Right click on the Start Menu -> "Installed apps"
2. Search for my app in the list, click the 3-dots menu and select "Uninstall"
3. Click to confirm the uninstall

Expected result:

1. The maintenance tool (= uninstaller) is shown and we can uninstall from the UI.

Actual result:

1. A window appears for a few milliseconds and closes immediately. It looks like the uninstaller but disappears so fast that it's hard to tell for sure.
2. It appears like if another window pops up as well for a few milliseconds, looking maybe like a console, but it's very hard to say.

What I tried so far:

1. Running the uninstaller.exe in the install folder through Windows Explorer or command line works well, the uninstaller UI is shown and I can uninstall (the name I chose for the Maintenance Tool is "uninstaller")
2. I checked the Windows registry under Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall
   {UUID}

   to verify that the UninstallString is correct.

   1. It points to the right path, with \ everywhere and quotes around.
3. I tried Start Menu -> Run with the exact string value as the UninstallString above: it works, the uninstaller is shown correctly.
4. I tried to replace the value of the registry key from
   1. 1. "C:\Program Files\Flyability\MyApp\uninstaller.exe"
   2. To the following
      1. powershell -Command "& 'C:\Program Files\Flyability\MyApp\uninstaller.exe'"
   3. And it works as well to uninstall from the Windows "Installed Apps" -> Uninstall.
5. I also tried to point to a simple bat file from the registry, with the exact same line in the bat file: "C:\Program Files\Flyability\MyApp\uninstaller.exe" and it works as well !
6. I checked whether anything was written in the Event Manager, but I found nothing.
7. I tried to change the registry value to point to any other software like Notepad, and Notepad is well shown when I choose Uninstall, as expected. So this seems really related to this executable.
8. I tested on a 2nd computer, with the exact same result, i.e. it does not work.
9. I tried to capture the output of the uninstaller when it fails, but I did not manage because as soon as I use a powershell script to do so, it work.

Other notes:

1. The same project built with Qt IFW 4.6 was working fine, uninstallation did work well. But I could not redo the test with the exact same conditions only switching to 4.6 yet as many things have changed on our CI since then.

So I really struggle to understand why it exits immediately by default.

Does anyone have any idea what could be happening ?
This is a blocking issue to release a software using Qt IFW currently as uninstall is not functional.