Welcome to the community, @dentonflake! I'm happy to hear that you're working with custom components - they've become one of my favorite parts of the product.
My initial impression is that the behavior you're describing is intended, in the sense that changes to state variables are expected to cause the component to re-render. When this happens, the table content is populated based on the params being passed into AgGridReact - rowData, columnDefs, and defaultColDef.
Your onStateUpdated handler likely needs to update the above values in addition to calling setGridState. Let me know if I'm misunderstanding some aspect of this! If you think it would be helpful and the timing works out, I'd be happy to help out during Office Hours tomorrow.