Cannot build a list of objects

I cannot figure out what’s not happening here.

I have a repeating list of checkboxes built by reading from a app variable. The idea is that checking the box would put the object represented by the checkbox into another app variable (a list of objects), but it is not working. Here’s the logic:

Clicking the checkbox brings an “if” choice to check the state of the checkbox (side issue - the checkbox is not graphically changing states when tapped like others on the page, even though the onChange event is firing) then it fires an alert to check the value of the incoming information:

Then it is supposed to put this object into a list of objects at the app level:

after that, it’s supposed to show that the list of objects has received the object:

I have a similar logic flow created that works correctly, so there’s something wrong with the code somewhere… but the first alert box is a copy of the same formula calls used in the WITH_UNIQUE_KEY. The code is executed successfully, because the second alert box fires - But the receiving app list of objects does not ever get added to.

Where is my error?