Composite Model - Plotting attributes from the fact table

Hi

I am currently working on a composite model in Power BI Desktop, where I combine a cooperate SSAS tabular model with an excel sheet, placed in our Azure Data Lake. I am facing some problems, and hope that you can help me:

When I add a new fact table from my excel sheet, the relationship seems to go wrong when plotted. So far I managed to go about it by creating a measure, that is taking MAX(column). But it is not optimal that a character attribute, suddenly is listed as a measure. Does anyone have a solution for this?