The Elder Scrolls: Oblivion Remastered comes as quite a surprise. Launching nearly two decades after the original, the game was outsourced to a third-party studio. Instead of the Creation Engine or ID Tech, the remake uses the Unreal Engine 5. And we all know about UE5s problems.
Source: N4G PC Elder Scrolls Oblivion Remastered PC Optimized Settings & Performance Guide