Stream statistics are not collected

We started integrating with Cloudflare Stream for uploading videos (via link) and showing them (using the Stream player) on our website. And we would also like to track the number of minutes viewed.
At first, the per-video and bulk analytics worked fine, but at some point they stopped including data on the latest views, as if the videos had not been watched. Perhaps the last day when some statistics was captured was February, 10. If I watch videos now, there will be no new data available in the statistics.
I tried watching videos on different devices using different browsers, uploading videos with different duration, fetching per-video analytics and GraphQL bulk analytics, filtering by different time ranges, uploading videos via our implementation using .NET’s HttpClient and via cURL, uploading from different hostings (filestack and amazon), deleting videos uploaded earlier, watching using <iframe> and via the special preview link (like https://watch.cloudflarestream.com/8d717d9d1b0920ea247a4eebd747b1fd), viewing with preview Stream Player 2.0. Nothing worked.
Steps to reproduce problem:
Upload some video, wait unitl it is ready to stream and watch it (probably a few times so that the total view time is more than 1 minute) (follow these steps: https://developers.cloudflare.com/stream/)
Fetch bulk analytics using appropriate date range filter (https://developers.cloudflare.com/stream/getting-analytics/fetching-bulk-analytics)
Actual results:
The response JSON is {"data":{"viewer":{"accounts":[{"videoPlaybackEventsAdaptiveGroups":[]}]}},"errors":null} where
videoPlaybackEventsAdaptiveGroups is an empty array (or at least does not include any info about the video you just uploaded)
Expected results:
The videoPlaybackEventsAdaptiveGroups array should contain an entry like

 {
    "dimensions":{
        "uid": "<the uid of the video you uploaded and watched>"
    },
    "sum":{
        "timeViewedMinutes":1
    }
}

Screenshots:
Above on the screenshot are bulk analytics and per-video requests and results; below on the Network tab of the browser developer panel you can see that the player does periodically send requests to stats.videodelivery.net and the response HTTP status is always 204 (success) which indicates that the metrics data should be received by Cloudflare: