My mistake, found out the issue was me declaring ajax call response data type 'json' which should really be 'html' since I'm returning a PartialView from controller.
However, there's still issue with the grid, I can only see the table header and all rows are blank, there is an error coming from infragistics.ui.grid.filtering.js: "Cannot read properties of undefined (reading 'getEditor')" not sure if this is related?
