Hi there Michael, here is what I am getting using Project, with only the case of projecting against an object behaving as expected. Odd ...

https://www.youtube.com/watch?v=3732ycAvdjU

The test file is attached.

[edit] ... aaaand I am now realizing that even though "Top" is already selected in the list picker, the tool requires an actual click on the "Use Cplane" button to operate. That's all there was to it :)

For the sake of improved UX I would suggest to flip this around to put the operations in the natural left-to-right order : picking from the list (on the left), then pressing the button (on the right). Preferably with a disambiguation built into the text prompt guiding the user, stating clearly that the button needs to be pressed.