Jellyin app on steam deck allows screen to dim

The jellyfin app (self hosted video streaming) app on steam deck (installed via desktop mode->discovery as a flat pack) doesn't seem to register as 'playing' with the os. The screen will dim after a few mins.

I'm 'playing' the jellyfin app as a non steam game in game mode.

I know I can disable screen dimming in the settings but is there a way to have it auto detect when a video is playing and prevent the screen from dimming?