There is a workaround.
Create an empty ACTOR Blueprint.
Drag the BP to the Level. Attach the Character Device to the BP (by dragging and drop in the outliner).,
Then scale the BP Actor.
However, I’m seeing this stops working sometimes. Hard to repro.
A quick update.
If it stops working for you, you can just reset the Actor Scale.
Then reset the Character Device to the default Character.
Next select the Character you want again and finally scale the Actor back to the scale you want.