Strange verb detection for a common sentence

const sentence = "Developed backend for real-time AI communication";
const verbs = doc.verbs().json();

console.log(verbs);

[
    {
        "text": "backend",
        "terms": [
            {
                "text": "backend",
                "pre": "",
                "post": " ",
                "tags": [
                    "Verb",
                    "Infinitive"
                ],
                "normal": "backend",
                "index": [
                    0,
                    1
                ],
                "id": "backend|00200001O",
                "confidence": 0.7,
                "chunk": "Verb"
            }
        ],
        "verb": {
            "root": "backend",
            "preAdverbs": [],
            "postAdverbs": [],
            "auxiliary": "",
            "negative": false,
            "prefix": "",
            "infinitive": "backend",
            "grammar": {
                "form": "simple-present",
                "tense": "PresentTense",
                "copula": false,
                "isInfinitive": false
            }
        }
    }
]