Keynote 9.3 Scale Action being applied 2x

As per a previous thread, Keynote is having a problem when you apply a Scale animation to a picture. When the slide deck is played, the scaling animation is performed (correctly), followed by a "jump" where the scaling is applied a second time. Note that it functions correctly in the editing view when you "Preview" the action. Steps to reproduce:

1. Create a new blank Keynote slide.
2. Insert a picture (either through a dialog box or drag and drop).
3. With the picture selected, apply a Scale Action (Animate button > Action tab). It can be any value other than 100%.
4. While still in the Action tab, click the Preview button. The animation is shown correctly.
5. Play the slide deck. (If the Action is triggered by On Click, do so.)

Expected Behaviour: The image will scale as specified (including Acceleration options).

Actual Behaviour: The image is scaled correctly with the applied options, then suddenly scaled the same % again without any acceleration options — essentially, it appears to "jump." (e.g., an image with a 150% scale action will end up suddenly expanding to 225% of original size; e.g.2, an image with a 50% scale action will scale to 25%).

I tested this on macOS 10.2.6 (build 16G1212). I'll try to test in 10.13.3 as well.