Support for SermonSpeaker 5.x is in bugfix mode only, the same as it is for Joomla 3.10.
I will not add any new features to this releases.
Please upgrade to SermonSpeaker 6.x and Joomla 4.x, which is better anyway.
The list will always show the player in the mode it is set to show. So if you set the "priority" or "mode" to audio, it will always show the audioplayer only. Even if only videos are available. The singlepage on the other hand will adjust itself to what is available. In your case you want to switch to video. Then the video will also be shown. If it currently plays only audio it means that the player is working fine, but in audio mode.
You have a JavaScript error on your site. You probably have enable GoogleAnalytics support without actually including the code for Google Analytics on your page. You need to do that using one of the many available modules or plugins in the Joomla Extension Directory. Or disable Google Analytics support if you don't need it.