No results with segment duration ≥ 15

[Rapha149]

Basically what it says in the title: whenever I pass a segment duration of 15 or greater to the recognize method it returns no matches, only this:

{
    "matches": [],
    "location": {
        "accuracy": 0.01
    },
    "timestamp": 3476099292,
    "timezone": "Europe/Moscow",
    "tagid": "FC212090-1ABB-4CEF-87E6-D341DF994C80"
}

When I pass a segment duration of 14 or lower it works (with the same file).