I just switched from the S23U to the S25U and in the navigation menu, there is no longer the option to have swipe from bottom (works like buttons), just the swipe from sides.
You need to get the "NavStar" Plugin and "enable extra gesture seetings" within the app. Afterwards the 3 Button gesture is avaible on the normal spot.
The latest update from NavStar for One UI 7 may take some days to appear to everyone