Relationship not working (One to Many)

Hi! First of all i want to say that i've been searching for a solution for over a week. I have a pretty complex PBI database which we've been using for over a year. 

Last week i added some excels with information created by hand. I have a situation where there's a "many to many" relationship to be made so that we can relate this new information to the older data. I tried to simplify debugging by bringing up just 2 tables which have this "many to many" relationship. First (by doing some research) I created a new table using the column that should be related to the second table and deleted duplicates. So now i have 3 tables: 
1. Older Data with a "Receipt" column

2. Recently uploaded table with a "Receipt" column

3. Created table with only one column (receipt) where i deleted duplicates. 

Next step, I'm trying to create a relationship between tables 2 and 3 but i get different records being related. For example: Instead of getting a relationship like 1000 > 1000, i get 1000 > 1089. 

I cant see what the problem is.

This is the File: https://drive.google.com/file/d/1l48eZwVTVax6RVswh3TySFVLIIYogxId/view?usp=sharing