From the imprint, it looks like somebody gronked on a wedge clamp stem too high up and without the Cannondale reinforcing plug in place.
And this is why you don't buy second hand carbon.
Yep just hoping the imprinted bit hasn’t weekend the carbon, was going to fit one of the longer colnago expander plugs and move stem down so the top section is just a spacer or summit
Got the top cap - cheers
went to fit it and found a crack/chip on the top of my steerer FFS