It just keeps getting pushed back further...
Now they need to dig even deeper after they think they ran out. Below that iceage layer there are even older finds that are not supposed to be there.
There are pre-pre-clovis down there to be found...
We always stop digging far too soon with all these. And it is financially dictated that we do stop too soon.
As one of my old professors once said “The Earth is an Icy Planet with vast areas suffering from long term cold. However it is punctuated by warming lulls, thats when civilization happens!”.