Animation Window undo error in rec mode after preview offset

Getting an InvalidOperationException error after the following operations in the Animation window.

This can be reproduced with a single cube and two keys.

repro:

• create a cube with 2 keys moving the cube over time in the Animation window
  or
• open attached project and test scene, open the Animation window and select cube in the scene
• scrub the animation window time ruler to activate Preview mode and set current time half way through the animation
• now offset the cube in the scene window, more than once
• now immediately click the red button to set the Animation window into record mode...
• Ctrl-Z (CMD-Z) to Undo the operation...
  bug: error in the console

see arrached gif

Alternative repro:

• scrub the animation window time ruler to activate Preview mode and set current time half way through the animation
• now offset the cube in the scene window once
• RMB-Click on the animated property in the Inspector and select Add key
• Ctrl-Z (CMD-Z) to Undo the operation...

InvalidOperationException: AnimationMode.AddCandidates may only be called when recording candidates. See AnimationMode.StartCandidateRecording.
UnityEditorInternal.AnimationWindowControl.ResampleAnimation (UnityEditorInternal.AnimationWindowControl+ResampleFlags flags) (at /Users/bokken/buildslave/unity/build/Editor/Mono/Animation/AnimationWindow/AnimationWindowControl.cs:686)
UnityEditorInternal.AnimationWindowControl.ResampleAnimation () (at /Users/bokken/buildslave/unity/build/Editor/Mono/Animation/AnimationWindow/AnimationWindowControl.cs:628)
UnityEditorInternal.AnimationWindowState.UndoRedoPerformed () (at /Users/bokken/buildslave/unity/build/Editor/Mono/Animation/AnimationWindow/AnimationWindowState.cs:432)
UnityEditor.Undo.Internal_CallUndoRedoPerformed () (at /Users/bokken/buildslave/unity/build/Editor/Mono/Undo/Undo.bindings.cs:237)
UnityEditor.EditorApplication:Internal_CallGlobalEventHandler() (at /Users/bokken/buildslave/unity/build/Editor/Mono/EditorApplication.cs:428)

this bug is present in all versions back to at least 2019.4 and current 2021.2