The driving behavior for speed bumps isn't to always slow down but to "attempt to go no faster than 18mph" for the longer speed humps and 6mph for shorter speed bumps.
@Frenchie's latest video had 10.4 taking 3 speed humps too fast:
17mph,
20mph and
18mph; and he commented that he would prefer 16mph.
Part of it is the neural networks might be late to detect these speed bumps/humps, so it doesn't have enough time to smoothly slow down to the target speed, but more training should improve that prediction. The other aspect is that the target speed might be too high for some people. Separately, I just learned that Chicago downtown's default speed limit is 30mph, which is higher than many residential areas set to 25mph, so that could also contribute to his roughness of needing to slow down from 30mph to 18mph whereas other neighborhoods only need to slow down by 7mph instead of 12mph.