If you are using a non-brand cable with no certification whatsoever, that could be the reason as well. 2 yrs ago I bought an usb c-hdmi cable and the brand boasts authorized and certified DRM content mirroring.
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If you are using a non-brand cable with no certification whatsoever, that could be the reason as well. 2 yrs ago I bought an usb c-hdmi cable and the brand boasts authorized and certified DRM content mirroring.