API returns incorrect entity links (wrong diffbotUri), low confidence scores, or misses coreferences/pronouns in entity resolution for Natural Language API calls.

No documented technical root cause found; entity resolution in NLP APIs like Diffbot's is probabilistic and can fail on ambiguous pronouns, rare entities, or noisy text (inherent to ML models, 91.21% entity linking accuracy per [Diffbot benchmarks](https://www.diffbot.com/products/natural-language/)).