EftPOS Cash Out with Ticket Sale

You pictures aren’t loading for me but if you creating account transaction outside of a ticket payment that wouldn’t be reflected in default reports as it is reporting ticket details not account details. You would need to adjust the report to account for this.

I made 2 sales for the same item and paid one with cash and one with credit card cash back.

The result is that my payment report says that I’ve received 300 on credit card and 234 in cash. This should be 300 cc and 168 cash (234-66 cash received - cash back)

Your pictures from before didn’t load so don’t really know what you have setup.
But as I said before if you are reporting ticket payment details this is correct, the ticket was paid with 300 card and 234 cash. the background account transactions are not ticket payments. You would need to tweek the report to shown more than just ticket payments.
The key bit to check your calculation settings is to look at the accounts screen rather than ticket payment details on default report.

That report is correct. The cash back is not a payment. You would need to see accounting or build a custom report to show cash account balance.