Setting a Frame Number Struct via Blueprints

I am setting the End Frame Offset property of an animation in a level sequence.
When setting manually everything works correctly.
I’m trying to set this via blueprint and not getting the same result.

Here are the issues I have:

  1. When set via blueprint the number in the editor window has a * / asterisk next to it. What does this mean?

  2. In Blueprint, I have accessed the MovieSceneSkeletalAnimationParams. When I try to set the End Frame Offset (Frame Number Structure) in BP it limits the range in the editor window (any negative value I use in BP variable reverts to -001 and if positive to 0000). For example if I set the variable to -2 or -24 it shows -001* in editor. If I set the variable to 2 or 24 it shows 0000* in editor.
    How do I properly set this in Blueprints?

PS Please excuse the phone captures, I’m working on a locked-down production box.

Additional note: Also tried to set this via Python script with the same result.
Code:

params = unreal.MovieSceneSkeletalAnimationParams()
params.set_editor_property("end_frame_offset", unreal.FrameNumber(-2))

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