In case none of this methods work, check this other post, AMD FSR 1.0 for Unreal Engine 5 - (AMD FidelityFX Super Resolution) - #9 by lucoiso, here the user lucoiso links to a github page with a compiled plugin of AMD FSR for UE5 (a plugin for rendering at lower resolutions and upscaling the screen), it can give you extra performance and is GPU vendor independant , a guide can be found here How to use AMD FidelityFX Super Resolution (FSR) 1.0 Unreal Engine 4 Plugin - GPUOpen , or try DLSS if you own nvidia hardware and if it’s UE5 compatible.