Repro for the issue dotnet/winforms#10746 also published on https://developercommunity.visualstudio.com/t/CancelEdit-property-has-no-effect-does-/10572240
A video of the differences can be found:
This is literally the sample code from: https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.listview.afterlabeledit?view=windowsdesktop-8.0#remarks