Vlad The fact that is works with clean profile suggest to a setup issue in the existing one.
Perhaps, but there are a lot of variables between the two.
Vlad Have you tried Develop -> Empty Cache?
Just tried it now, and it seems to have had no effect on the issue.
However, some additional information that should be useful: I just restarted Orion to install the new update (nice job, btw), and I was able to determine with some further testing that the issue only occurs after a page with audio or video is loaded at some point. The issue persists even after that tab is closed, but does not occur before such content is loaded.
So far, triggering events have included watching a video on YouTube, playing an embedded audio file on a webpage, and loading a local video file via file://
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