I may have found the problem. I have multiple GTAV folders, so that when I mod GTAV, it doesn't screw up anything for Online for me. This seems to be the problem, I haven't fully tested it yet but it seems when I launch GTAV from my modded folder, it's still actually loading the game from my original GTAV folder, not the modded one, thanks to the new Rockstar Launcher which appears to always want to launch from the steam directory instead of where I'm actually launching the game from. Of course this is for the steam version only. @celediel do you have multiple folders?
The test that came from this that I personally did, was just to simply install an ENB, when the game launched it wasn't even loaded and that doesn't need anything to load. So this is probably the reason why dinput8 and scripthooks don't appear to be working, at least for me, because its not even launching the game from the right directory. I have no fix for this currently unless you just mod your original GTA folder. There is currently no LauncherByPass mod that fixes this.