Please help me find an error in my workflow and explain it

Hey there! attached is my n8n workflow. it sends monthly reports to customers. each report includes all the orders relating to certain contract number, i.e. to create a monthly report orders are grouped by the contact number.

The actual reports generated by the workflow (provided in the json file) included only part of the orders and were sent to wrong emails. Please help me find an error in my workflow and explain it. Any suggestion on how to improve my workflow are welcome.

not able to upload the json file (getting an error while trying to upload) so posting the code in the comments below. Can I attach a json file here?

here is the link to json file:

Debug info

## core

- n8nVersion: 2.4.6

- platform: docker (self-hosted)

- nodeJsVersion: 22.21.1

- nodeEnv: production

- database: sqlite

- executionMode: regular

- concurrency: -1

- license: enterprise (production)

- consumerId: 0aeb59b9-99c7-451e-9aac-c5f8b4e38e39

## storage

- success: all

- error: all

- progress: false

- manual: true

- binaryMode: filesystem

## pruning

- enabled: true

- maxAge: 336 hours

- maxCount: 10000 executions

## client

- userAgent: mozilla/5.0 (macintosh; intel mac os x 10_15_7) applewebkit/537.36 (khtml, like gecko) chrome/145.0.0.0 safari/537.36

- isTouchDevice: false