Plasma Browser Integration: In the Media Player, the video has stopped working.

After reinstalling the system, I noticed that in Plasma Browser Integration, videos are not displayed in the Media Player, although everything was working fine previously (before the reinstallation). (I talk about a small player that opens from the icon panel and displays the video playing on YouTube or elsewhere. It can be pinned to the corner, allowing multitasking while watching, for example, a tutorial. All of this used to work before, but not anymore.) Any ideas, how to fix it? Thanks.