Have you published your Power BI report to the service, refresh the data, and the visuals go blank? Patrick may have an answer for you.
Troubleshooting refresh scenarios
https://docs.microsoft.com/power-bi/connect-data/refresh-troubleshooting-refresh-scenarios
Data types in Power BI Desktop
https://docs.microsoft.com/power-bi/connect-data/desktop-data-types
Damu Venkatesan:
https://twitter.com/vdamu
https://www.linkedin.com/in/damuvenkatesan/