Remembered yesterday that I had forced the game to run with Win XP SP3 compatiblity, which is why the option didn't show up anymore. Removed compatibility and option returned, so np.
Are you by chance running the game in compatibility mode for Windows XP? I had forgot that I had put mine to try Windows XP compatibility to see if that resolves some issues, which removed the option for me in the drop-down menu.
Also tried to reboot my computer, and I saw in another thread a command to disable DX11 for Intel Integrated Graphics issues, so I tried to change that from "-d3d11Enable 0" to "-d3d11Enable 1" to see if this had any effect, but that was also without any luck.