Hello Basj
Here is the probable cause. Uninstalled Start 11 ver2.53 that included the current update - removed all traces from the Registry and left over folders.
Installed the V2 of Start 11 that dates back to Dec 2024, i.e. before the current update.
No issue with the Start Button selected to Biohazzard, or any of the others.
That points to some sort of issue with the current update - at least on my machine, which is a standard Windows 11 Pro setup.
Perhaps of note with experimenting in the last hour or so - the current V2, that includes an update to the version dated Dec 2024, would load a different Start Button than the default upon a restart of Windows - sometimes. That tends to point to Windows having a problem either finding, or loading, the selected Start Button other than the Windows default?
I've not check what happens though if the most recent update to Start 11 is implemented.
Hopefully if someone else runs against this, the above solution may work.