Ok, I have a 2018 RGS brought last November. I have read of this issue on another forum so looked out for it.
At 3000 miles I saw my levels was low, went to my local dealer and reported it, at first they said they didn't know what I was talking about, however I had the service doc with me. They checked my bike and said nothing came out of my transmission and excess oil gushed out of my primary!
They contacted HD who told then to drain and refill to correct levels and ask me to ride 1000 miles and bring back for checking, this I did, unfortunately no oil was transferred so nothing further happened, however I was told my bike now has a reference number in the HD system so if a fix was found I SHOULD be contacted.
The 'fix' Harley has does NOT resolve the problem, in some bikes it slows the transfer down but not fix it.
There is only ONE real fix, a guy on HDForms.com has examined exactly what is going on and produced a fix, new seal and venting.
I suggest all concerned members take a look at this thread, its very long. Go to the end to see what the fix is and the cost.
Heres a link to the thread:
I did speak to Harley about this 'fix', they told me if I put it in my bike it would void my warranty, even though it fixes a known problem HD cannot solve!
BTW, my bike is stock except for slip-ons and I ride normal, not tear the ass out of it, single rider most of the time.