You have to add edit button inside the Grid countrol bar.
in that you can call the view/Edit page.
I think you have Added a Create Button in the Datagrid which will always create a new Object.
Instead you should add a action Button in the Datagrid controls, which will expect a object to be selected from the DataGrid.
Accpet my answer if the solution works for you ATB!!
You need to call a microflow and in the data view/ listview the object should be the same input to the microflow and you need to call the edit page.