Both processing and plugins use the same DOP window. There’s no issue here.
For example:
- selecting Gain (processing) opens the DOP window with Gain applied (or ready to be applied)
- selecting Studio EQ (plugin) opens the DOP window with Studio EQ applied (or ready to be applied)
So the end result is not the same.
My guess is that you are using these commands without having first selected an audio event…