It’s been reported by a number of our users when getting started with their audio streams in Radio Station PRO that a stream will not play in our persistent audio player bar or widgets. This happens when a stream URL starting with HTTP forces a mixed content error in the browser. Browsers will display mixed content errors in the Console for media assets like images, documents, audio, and video if they are not uploaded to a site secured with HTTPS. This is also true for stream URLs.
Even if you ask your WebHost to secure your site with HTTPS, your stream URL may be coming from a different streaming server. For example, the site in the image featured here resolves at a URL starting with HTTPS, but the stream URL is coming from a server that is not secured, so the URL resolves at HTTP.
To fix mixed content errors for audio stream URLs, you should ask your stream host to provide you with a secure HTTPS version of the URL. If you are hosting your stream on your own server from your own domain, you can use a WordPress plugin like SSL Insecure Content Fixer to resolve it for you. Using a plugin will not fix mixed content errors when your stream originates from a third party that is on their domain. They’ll need to provide you with a URL secured with HTTPS.
To learn more about mixed content errors, view the What is Mixed Content? article on Web.dev and read this tutorial from WP Beginner on how to fix mixed content errors.