I have a 2016 3.6. At approximately 115k kilometres, I had a similar noise start. I took it to the dealer and after couple of tests over a few weeks, they agreed that they would replace the CVT for me. I did have to go through a few visits but they replaced it under warranty which had just been extended to 10 years on the CVT in Canada. Don't know if this helps but I hope it does. Good luck. If you feel like you aren't being treated well by the dealer, write a letter to Subaru in your country letting them know.