Scheduling localhost serverless cron: The model could not be resolved in registry - express

Question

I'm hosting an ExpressJS/NodeJS API on AWS Lambda with Serverless framework. The API uses Knex.js and Bookshelf.js ORM.
I want to test scheduling a cron job locally. I'm using serverless-offline-scheduler to do this.
Question: My API runs fine if I call it from my client, but if I call a function via serverless scheduler, it complains that no models are in the registry. Why is this? I've already definitely included all necessary Models at the top of the OrderService.js file.
{
"errorMessage": "The model User could not be resolved from the registry plugin.",
"errorType": "Error",
"stackTrace": [
"Error: The model User could not be resolved from the registry plugin.",
" at new ModelNotResolved (/Users/danielturcotte/Sites/d2c/api_v4/node_modules/bookshelf/lib/plugins/registry.js:70:133)",
Serverless.yml:
functions:
app:
handler: handler.handler
events: ...
dequeue:
handler: ./services/OrderService.dequeue // Call dequeue function
events:
- schedule: rate(1 minute)
The handler calls root/services/OrderService.dequeue function, which contains
...
const dequeue = async function() {
await checkQueuedOrders();
};
module.exports = {
dequeue,
};
In my knexService.js file, I register Bookshelf models to the registry to remove circular dependencies:
const knexfile = require('./knexfile');
const config = require('./environment');
const environment = config.env.NODE_ENV || 'development';
const knex = require('knex')(knexfile[environment]);
knex.client.pool.numPendingCreates();
const bookshelf = require('bookshelf')(knex);
bookshelf.plugin('registry'); // Resolve circular dependencies with relations
bookshelf.plugin('visibility');
bookshelf.plugin('pagination');
module.exports.knex = knex;
module.exports.bookshelf = bookshelf;