I have a shape layer animating up and down with just one keyframe. How is this possible?

Hi. I'm working on editing a large Figma project that includes some animations done in After Effects.

My knowledge of After Effects is pretty basic.

There's one issue I'm running into that I can't figure out and was hoping someone here might have the answer.

There's a rectangle shape layer (named: Rectangle 4945).

The comp is 5 seconds long.

When previewing the comp, Rectangle 4945 moves up vertically and at 0:00:02:19 it changes direction and moves down vertically towards where it started from.

Indeed, if I check it's Position property, there's a keyframe at 0:00:02:19 set to the Y position where it changes direction.

However, it's the ONLY keyframe. I was expecting to see a keyframe at the beginning of the comp with Y set to its starting vertical position and another keyframe at the end with Y set to its end vertical position, but there are no other keyframes except for the one at ...02:19. 

Here is the layer with playhead at first frame. Note position is -95.9, 514.9 and there's no keyframe there.

Here is the layer with playhead at 0:00:02:19, where there's a keyframe. Notice that now the position is now -95.9, 438.9

At the end of the animation, as in the first frame, there is no keyframe either, yet the Y position at this point changed and is now 515.1.

It did not escape me that Rectangle 4945 is linked to a parent layer - "Null 132". But I checked and Null 132 has no animations at all. I seleted Null 132 and hit the key U and nothing showed up. I expanded the Transform properties and I see no keyframes. So the vertical animation is not being brought in from a linked layer

I can't figure out how Rectangle 4945 is moving up and then down again with just one keyframe.

The epxression for Position is just the standard "transform.position"

Any ideas?

The only thing I can think of is when I opened the AEP file, I was prompted to convert to the most recent version of After Effects, so maybe this was created in an earlier version and somehow this is causing the start and end keyframes not to appear?