@joagomez, I noticed you added streamlink to your Docker image. There's a bug/misfeature in streamlink that I've encountered before and it's affecting your latest image, at least for me. The bug is that when choosing a stream, streamlink uses the first stream with the highest resolution and ignores the frame rate. In my case, Fubo often lists the stream with the highest frame rate second. For example, for a normally 720p60 stream, Fubo gives them to me in an order like 720p30, 720p60, 480p30, etc. I even have at least one case where this hapens with 1080p too. For my local, CBS affiliate, Fubo lists the streams like 1080p30, 1080p60, 720p30, 720p60, etc. As a result, I often get a lower frame rate than I should using your latest image. FWIW, I've worked around this issue in the past by using yt-dlp instead of streamlink as it does a better job of choosing the "best" stream.
An easy way to check for the problem is to play the HLS stream with mpv. Mpv lists the available streams in the order provided and marks the one that it chooses as best.