Try adding @key [@key="selectedCategory"]in your code.

<MudDataGrid @ref="dataGrid" @key="selectedCategory" T="Element" ServerData="ServerReload" Filterable="false">..

The Key parameter in Blazor is used to help the rendering engine identify components uniquely. When you set a Key on a component like , it forces Blazor to treat it as a new instance whenever the key changes, which can be useful for ensuring a fresh re-render.