Ring dependence for connection

Hey there,

The following situation:

I have 4 tables in PowerBI desktop:

1. manufacturer table
2. positions table
3. order table (Summarized from "position table)
4. position table (Summarized from "position table)

Now I want to create a connection in the data model. There is already a connection between 1. and 2. as well as 4.

As soon as I want to create the connection between 1. and 3. the following error message appears:

Can anyone help?

Greetings
Finn