Try the following steps with any media player on your device. If the data is on the SD card, copy the file to the device's memory. Then try to play the data. Please note that it is best to use only Mp4 data as a movie. Otherwise there is an alternative with Libertine and the Kodi Mediacenter with effort. You can also try the hint with audio data.

@mardy Yes, this is not a regression caused by the new media hub. This behavior was present from the start.

I had the issue of the sd card not mounting at all on my Poco F1. This has helped me. You can try it out. https://askubuntu.com/questions/95391/how-do-i-mount-an-sd-card