Samsung S9 ignores the "light ons" signal sent by cars. Mine ins a VW Golf and it works just fine with Apple Carplay which turns automatically to nigh mode when I enter a tunnel and resumes to day mode when I exit the tunnel.
But when I connect my S9, the night mode can only be controlled by the phone, regardeless of what you chose in the (hidden) androd Auto parameters.
This is DEFINITELY a S9 firmware problem that Samsung rudely ignores. I t was alreay the case with the S9 Oreo firmwares. I an plannig to move back to Apple ... as many.
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