Having same issue over multiple devices running on Windows 11 24H2.
When windows 10 devices had Brother scanner driver installed and working perfectly fine, after upgrading them to windows 11 doesn't cause any issue, in fact it's still working on Windows 11 24H2.
But let's say some devices, we have installed fresh copy of Windows 11 24H2 due to some reason and then tried to install Brother printer full driver package installation, only scanner driver failed to get installed.
If anyone find any loophole to workaround, please post here to help other.
Microsoft/Windows - get it resolved... Or Brother need to find a new solution...