I'm using the August 2018 version of power BI desktop (dowloaden from the Microsoft app store)
Looking at a previous thread, draging queries in the query editor (Power Query), has been an issue before and it has come back:
Because it has been marked as solved in the thread above, I wanted to create a new thread highligthing this issue.
Moreover, the drag and drop feature for applied steps (as available in Excel Power Query) is also not working in power BI.
You may check the post below,
Speaking MSI version August 2018 and Microsoft Store version August 2018.
I do confirm that the MSI version of power BI desktop does support drag & drop for queries & applied steps!
The MSI version is that version which you can download from app.powerbi.com, in the top right you see a download button.
Unfortunately the Microsoft Store version does NOT support the drag & drop. I really hope the power BI team picks this up and fix this.