How many rows and columns in each of the Excel file? What is the size of your PBIX file? What detailed error message do you get when refreshing data in Power BI Desktop and Power BI Service? Complex data model and multiple transform steps in Power BI Desktop may eat a large amount of memory during the refresh and cause the crash problem. In your scenario, it is recommended to import required columns and rows into Power BI.
In addition, please make sure that you are using latest version of Power BI Desktop and Power BI gateway.