I have the same exact problem, after spending multiple hours using multiple disk images which I back up once a week and keep four weeks of there are actually two updates that cause this issue. I installed the updates in a different order and went from 2.3GB in update cleanup not wanting to "clean" to only 373MB. The two updates that cause this issue are.
2022-05 Cumulative Update Preview for .NET Framework 3.5 and 4.8 for Windows 11 for x64 (KB5013889
2022-05 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 11 for x64 (KB5013628)
It doesn't matter which one you install first they both cause the windows update cleanup under disk cleanup to persist after a cleaning.
From what I think it is just reporting this as persisting even though it does clean it up. After each trial I would do the cleanup and it would take the time during windows update cleanup that it usually does on first run. All subsequent runs it just rushes through the update cleanup like there is nothing there. My actual diskspace is correct, and Powershell cleanup shows it being cleaned.