Here's what ultimately worked for me on Windows 11 24H2

Set-ItemProperty -Path HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\ -Name SetPolicyDrivenUpdateSourceForQualityUpdates -Value 0
Get-WindowsCapability -Name RSAT.ActiveDirectory.* -Online | Add-WindowsCapability -Online
Set-ItemProperty -Path HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\ -Name SetPolicyDrivenUpdateSourceForQualityUpdates -Value 1

Credit to https://www.reddit.com/r/SCCM/comments/19ffhej/is_installing_rsat_still_broken/