When I queue up a number of podcasts to play in rhythmbox, the output device often changes when the second podcast starts, from a device connected via a USB port to the built in audio.  This happens when I use either the PulseAudio Volume Control application or the KDE Plasma Audio Volume applet.  I don't remember it happening under Fedora-33.

System

-- 

Thanks for your help Jonathan Ryshpan <jonrysh@pacbell.net>

	Dance, as if nobody's watching,
	Love, as if you've never been hurt,
	Sing, as if no one can hear you,
	Work, as if you don't need the money,
	Live, as if heaven is on earth.
	-- Rumi