Powerpivot slicers not working as expected in PowerBI

I am desperately trying to find ways to share tabular data in PowerBI but coming up short. None of the data visualizations really supports tables or matrix to my liking (expand/collapse, drill down, etc.) When I upload an Excel file that has a PowerPivot data model I get the dreaded "This workbook contains external data connections or BI features that are not supported" but I don't know why, I am not trying to refresh the data model, only trying to use slicers on the web page in Excel Online...someone please tell me this is supported?? What check box am I missing???