I would love to have an answer to this.
When I start my 2018 Outback, the radio is playing, even though I actively turned it off before turning off the ignition. At least when I turn it off, it stays off and everything else is normal.
There is absolutely nothing in either the Outback or Starlink manuals about it - that it exists, whether it can be changed...
Does *anyone* have a suggestion?
No, I can't take it to the dealer. In my town, they suck. I take it to an indie all-Subaru garage.
I'll ask them, and report back if they have ideas.
Side note - Japanese electronics companies have a long legacy of being hardware companies, with software being an afterthought to make the hardware work. I have years of first-hand experience with this phenomenon. I think the electronics in Subarus are another example of that.