New measure does not see any columns

[nahaku]

Hello, I am new in power BI, I was watching few youtube guides, but I cannot figured out why Power BI does not see any columns in any of my tables.
See the picture. They have relationship, and columns I want to use measure, have SUM as default aggregation.
here is the picture:

https://imgur.com/Lj5Y3rb

 

[nahaku]

Yea, when I made Quick Measure, it made this formula:
DIVIDE(SUM('Picking Data'[Items]), SUM('Picking Data'[Time])) * 3600
I am not sure why it needs the SUM there, when all the data columns are set tu SUM already, it is comfusing.