The vehicle will randomly beep three times when starting as well as randomly while driving it will beep the horn 1 or 2 times for a short beep. It is really annoying as people think I am honking at them or trying to get their attention or worse trying to startle them. I finally got sick of it and did some more detailed searches online and found it is likely due to the remote starter being defective.

In this other forum (https://www.subaruoutback.org/threads/horn-will-honk-3-times-sometimes-4-times-after-starting.527210/page-2) there indicates there is a service bulletin that tells Subaru service to install an older version of the remote start to fix, but people have complained that Subaru will not do it unless they can repeat the issue. Since it is completely random it is not able to be repeated. It may happen 1 out of every 10 or 20 starts or more. Anyway, I'm outside of warranty and likely to experience no better when I go to the dealer. Mine is a Subaru remote starter that I had them install when I bought the vehicle. I know there are many people experiencing this problem and would like to see how many complaints are issued against it. The Subaru service bulletin is 15-299-22. Hope this helps someone.