Epic storefront, Rockstar executable

Buying the game on Epic does not create an Epic-native trainer. You still attach to GTA5.exe after Social Club has done its part.

Turn Epic’s overlay off for Grand Theft Auto V. Do not stack ReShade, Afterburner, and a second trainer on day one. Sign in, load Story Mode until you can walk, then attach once.

If Epic verifies files, it is verifying the game, not the overlay folder. Keep Kiddions out of the install directory on purpose.