I can’t reproduce your issue. When I use that exact same request, all the VoDs that don’t have muted segments have muted_segments: null, and all the VoDs that do have muted sections appropriately return the muted sections in that request, such as
"id": "1262329755",
"stream_id": "44370393884",
"user_id": "29334085",
"user_login": "frozzyaka",
"user_name": "frozzyaka",
"title": "А вокруг ранкеды, ранкеды.... ранкеды ху.....",
"description": "",
"created_at": "2022-01-13T16:58:39Z",
"published_at": "2022-01-13T16:58:39Z",
"url": "https://www.twitch.tv/videos/1262329755",
"thumbnail_url": "https://static-cdn.jtvnw.net/cf_vods/dgeft87wbj63p/f36dd4db6175b7fdab0c_frozzyaka_44370393884_1642093111//thumb/thumb0-%{width}x%{height}.jpg",
"viewable": "public",
"view_count": 1810,
"language": "ru",
"type": "archive",
"duration": "6h43m31s",
"muted_segments": [
{
"duration": 360,
"offset": 0
},
{
"duration": 360,
"offset": 7200
},
{
"duration": 360,
"offset": 7920
},
{
"duration": 360,
"offset": 10080
}
]
}```