YouTube has implemented a new security measure to block third-party mobile browsers from accessing the background playback feature, which was previously exclusive to YouTube Premium subscribers on the official iOS or Android app.
According to an unnamed Google spokesperson who spoke to Android Authority, “Background playback is a feature intended to be exclusive for YouTube Premium members.” The spokesperson further explained, “While some non-Premium users may have previously been able to access this through mobile web browsers in certain scenarios, we have updated the experience to ensure consistency across all our platforms.”
Reports of the block initially surfaced from Samsung Internet users and later expanded to other browsers like Brave, Vivaldi, and Microsoft Edge. However, some Firefox users have found a way to maintain the background playback functionality by altering the browser’s user-agent string to Android VR.
Source: The Verge