If you are playing with a controller (I used the PS5 controller) and you are having trouble walking, make sure to go into the steam controller settings and edit the left analog stick deadzone. Whatever dude at Konami was told to make the official controller settings for the game accidentally made the deadzone 50%, so you end up having only a millimeter of leeway between walking and running, which makes sneaking over loud surfaces extremely difficult.

Edit: Looks like the issue isn't a Konami mistake but a default steam setting, check your default controller deadzones on steam instead of changing the games specific settings. Otherwise you'll have this problem with other games as well. I have no idea why steam would default to such a high deadzone for new controllers.