I have found a case where Power BI Desktop fails to correctly identify the one and only foreign key relationship in a very simple database containing only one "child" table and a related "parent" table. Instead of using the correct foreign key column in the "child" table, Power BI Desktop creates an incorrect relationship using another column.
I would like to submit a zip file contiaining the reproduction of this error. It includes a backup of the sample source database, a script for that database, and the PBIX file created by Power BI Desktop (February 2019 version), with the incorrect relationship.
Please let me know how I can submit that information to you. Thanks.