Tranny or Engine?

The CVT on my 2018 OBW Limited started to slip a week ago today. I dropped it off at the dealership - which is 1.5 hours from my home - on Sunday. The nice service writer called me first thing on Monday and I gave her detailed information on when was happening when. She called back to say that the tech performed a TB on the tranny and then sent the 'live data' to Subaru to see if the tranny will be replaced under warranty. So we waited. Waited some more. The dealership has been great at keeping me informed that Subaru has yet to respond. Today they told me that Subaru wants another test done to rule out that the issue not the engine. They said that they've replaced trannys only to find out that the engine was causing the problem. Has anyone heard of this before? Sounds like BS to me.

Unfortunately, since the car is out of service I won't have it to go on vacation tomorrow. We always take our bicycles using the receiver hitch but our other car doesn't have the receiver - so we're SOL.