So on an Xbox one S the game crashed right when you blow up the base so that you can build. When the game relaunched the mission is successful but all the Fnix walls are still up. Which in one way its great since they have high HP. However it’s not supposed to be that way. On discord it seems to be a common problem. On my series X it’s fine and the mission played out normally.
We’ll fix and prevent this crash in a future patch.
Sorry for the inconvenience and thanks for reporting