For iOS 14, Apple have changed the UI for date and time pickers across the system. This has also affected Site Audit Pro in relation to the Project Date field.
Our next update will address this so that the UI is displayed correctly. In the meantime, to change the Project Date:
1) Tap the Project Date field
2) Look to the bottom left corner of the screen. You should see the date there - tap this.
3) You should now be able to use the date picker and change the date as before.