DF tried running One X version on Series X to see if they can hit 60 fps like the PS4 version running on PS5 does. The answer... well, no, the game runs like on Series X in Quality Mode, "almost worse actually", according con Alex. Tom says ir runs 2 to 3 ffps slower indeed.
The reason for that is that apparently the games doesn't use Series X GPU to push for higher fps, but for better visuals instead (resolution, shadows, AO and motion blur). They think the game does the same on PS5 but since the Pro version runs at 1800p CB the threshold is different, and that might be the reason for the better performance.