Foot Contact” doesn't work after using “Flatten All Motion”?

Hi everyone,

I’d like to use the “Foot Contact” feature. From what ChatGPT explained, this function makes sure the avatar automatically snaps to the ground and doesn’t sink through the floor.

However, “Foot Contact” doesn’t work, and according to ChatGPT, it’s likely because I used the “Flatten All Motion with Constraint” option at some point. Is that correct?

And if so, is there anything I can do to get “Foot Contact” working—or at least make sure the avatar automatically touches the floor and doesn’t go through the floor?

Thanks in advance!
Greetings, Shirley