For a control, select a vocal cut that should be well-recorded recently - but seems to have distortion.* Then proceed with many experiments to locate the cause of the distortion. (This can take several days.)
A few suggestions: (1) throw a wool blanket over the coffee table in front of the listening position (2) unplug any HT gear - leaving only 2 channel powered (3) make sure that power cords aren’t touching or paralleling any signal cables (4) confirm that all cable connectors are firmly plugged in - including AC plugs (5) mark the speaker positions with tape, then radically change their location - not just the toe-in (6) any other experiments.
Good luck!
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* Years ago, when I had a similar issue, I selected Patty Griffin’s song, ’Let Him Fly’. Some of her high notes were painful to my ears. Now, they’re smooth as silk.
In my case, the solution was clean power - with special attention to the streaming head end - modem/router/access point. YMMV