Did you return settings to default yet, and remove the Inspector?
Could you post your ini?
Also, Nvidia recently released a new driver version. I would try downloading that and doing a clean install (custom install, check the box).
Next, if you haven't made any changes to the .ini, add the following line under [System.Settings] bAllowPostprocessAA=True
Note that with your resolution you may not receive the same results using AA, AF, QCSAA, CSAA, MSAA etc. Start with just AA at 4x for you screen size. That should cause a noticeable change in your game, if not... it's not working. From there, you would then try forcing AA using the Control Panel. Add ME3 by clicking on the Manage 3D settings, clicking the Program Settings tab, click the Add button, and navigate to you install directory (ie. * Mass Effect 3BinariesWin32MassEffect3.exe).
From there enable Antialiasing - Gamma Correction, and set Antialiasing - Transparency to 4x.
Again, if no changes can be seen, there is an underlying issue. Try reinstalling the game.
Mass Effect 3 Tweaks Mod Manager
Mass Effect 3 Coalesced Tweaks
ME3Tweaks Mod Manager is a Mod Manager that supports all three Mass Effect trilogy games, and is backwards compatible with mods designed for Mass Effect 3 Mod Manager. This program is designed to make it easier to install mods for the Mass Effect series for end users. This program will supercede ME3MM once it reaches feature parity and users of that program will be upgraded to this one. SegmentNext - 'List of Mass Effect 3 INI Tweaks to improve PC graphics and performance'.
Pc Tweaks Mass Effect 3
Mass Effect 3 Tweaks 8/10/2019 Find Interaction Objects More Easily Set the highlight distance further so you can see the orange parenthases from further away.