Dolby Atmos doesn't work on latest Apple TV 4K

I am using the latest VLC App on my Apple TV 4K 2021 (32 GB). I uploaded a video from my PC to the VLC app (drag & drop the video file in the browser).

The original video contains Dolby Atmos sound. The VLC player only plays it as Dolby Digital 5.1 but not in Atmos. I also tried to watch the exact same video with another app on the same Apple TV and it is played in Atmos correctly. Therefore, the problem isn't related to the Apple TV or the setup itself, but with the VLC app.

If you need further information, please let me know!