What I tried to do to fix it - TL-DR: I failed: In all three cases the overlay will not work. When admid is set by right clicking on the exe only v1. Running the exe directly (by double clicking) only v1. steam is displayed in the lower left-hand corner. When admin is set via properties and the game is run via steam v1. The problem persists whether at the main menu or in-game. This is true whether the 'run as admin' function is set in the exe's Properties or if 'run as admin' is selected by right clicking on the exe.
The Steam Overlay will not open if the PillarsOfEternity.exe is Run as administrator. Description & Steps to Reproduce the Issue: