Thank you for reporting a bug to Unity.
After reviewing the behavior, we've confirmed it aligns with the current design and intended use of the feature. We understand this may differ from your expectations or workflow.
The Samples value is not something you want to change regularly, and is why you have the option to hide this value from the UI. This value is something the user knows (ex: 10, 24, 30) and normally sets once, then will not touch again for a given clip. This value a very different from the property values that you want to drag in order to get the desired visual result in the viewport.
We will close this case as 'As Designed.' If you have feedback on how the feature could better meet your needs, please let us know - we value your input and consider it in future improvements.