Getting electronics buzz on bass (Carvin/Kiesel B25)

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I have a Bromberg model Carvin bass from like 2017 or so. I don't ever recall having issues with the electronics before, but since I started playing seriously again I've noticed issues with buzzing.

If I crank the highs up at all, there's a pretty serious electronic buzzing sound. I've replaced the battery and tried to check for any obvious electronics problems like loose wires.

If I flatten everything out, it's not as noticeable.

I can't get Kiesel to respond to support for it, and I don't know how to get it fixed (never had repairs done before). Should any luthier be able to fix?