Cannot seem to use any Object Functions

I have this object being returned from Firebase, and I store it into an appVar. I can see the object using ENCODE_JSON function (either on a form or in a Toast), but I have no success trying to extract the sub-objects with the other Object functions.

For example, I tried binding the field to these formulas:
ENCODE_JSON(LOOKUP(appVars.findmypaccar, “readTime”)) returns as blank, not even ‘null’
ENCODE_JSON(appVars.findmypaccar.readTime) returns as blank, not even ‘null’
appVars.findmypaccar.readTime returns as blank, not even ‘null’

There are no errors on the browser console specifically for this problem.

[{“document”:{“name”:“projects/paccar-matching/databases/(default)/documents/find-my-paccar/r6nWnkigDq3ro63jZZGt”,“fields”:{“LOCATION”:{“stringValue”:“Waiting for Modsub”},“MODULE_CUSTOMER”:{“stringValue”:“F31-1058-3231311”},“MODULE_MAHLE”:{“stringValue”:“8NA3231311”},“SEQUENCE”:{“stringValue”:“R27006R”},“CHASSIS”:{“stringValue”:“354140”},“LAST_SEEN”:{“timestampValue”:“2023-08-23T10:43:56.095Z”}},“createTime”:“2023-08-23T14:25:55.514292Z”,“updateTime”:“2023-08-23T14:25:55.514292Z”},“readTime”:“2023-08-29T20:27:01.672767Z”}]

Just for testing I loaded the payload from Firebase into a Data Variable, and everything worked as expected.

In my original design I wanted to get the data from the server only once and use it in multiple pages. As I understand, a Data Variable is defined only on a single page.