Walking animation feet stretch legs forward

default walking animation for a prefab model causing feet to walk forward stretched far ahead of body after a few steps. unfortunately I don’t have a way to get footage of it. Model starts off walking fine, but then the feet shoot forward a few steps ahead of the model, causing the model to almost become horizontal with the ground because the head stays in the same spot it’s supposed to be. Tried looking through everything but can’t figure out what is causing this issue, considering the only thing changed on the model besides textures was a facial expression or two. any ideas? It did not do this prior to any editing.