Especially in places where segmentation-level ambiguities are involved.
Probable cause:
Concraft tries to assign EOS markes to segmentation-ambiguous edges.
Some of such edges are not chosen and their total probability mass is around 0.
Concraft nevertheless considers EOS markers for such highly improbable edges, and some of them get marked with EOS. Concraft relies on probabilities when deciding whether to mark a given edge with EOS, it is thus not surprising that it does not work for edges with total probability around 0.
Improbable or not, if an edge is marked with EOS, Concraft uses it to cut the sentence DAG in two.
Especially in places where segmentation-level ambiguities are involved.
Probable cause: