Safari stops playing videos after certain time open

In the latest version of desktop Safari (26.6) on my Mac mini M1, macOS Tahoe 26.6.1, on several occasions once the software has been open for some time, all videos are unable to play. Embedded videos display an error (dependent on which platform it's on - YouTube, Facebook etc.)

The only way to restore playback is to restart Safari.

It doesn't happen on every session, but often enough. I've never seen this behaviour before - but has exhibited it for about the past month or so. All other aspects of browsing are fine. Has anyone else experienced this?