@ZachSaucier thank you for getting back to me!
I've created a minimal demo here. If you pause and resume the child timeline, you can see a big jump because the parent is still calculating the child's position.
https://codepen.io/tylerlwsmith/pen/VwavGEK
Below is a first pass at language describing this behavior–I'd love to see something like this mentioned on the timeline pause() method page.
"When a timeline is nested within another timeline, the parent timeline will continue to calculate the animations of the child timeline, even if the child is paused."