Keep in mind that the first time the oil is changed it's not easy to find the crush washer. I've owned a lot of Subaru's and it's always the case. Because they paint the oil pan after they put the plug is installed, the crush washer is stuck to the plug and camouflaged. Sometimes it takes a knife blade to separate it from the plug. I've known a number of cases where people didn't think one was there and installed one so they had two. That will cause leaks.
I always install the Fumoto Oil Drain Valve, it makes things a lot easier. I have this one ready to install next oil change.
https://www.fumotooildrainvalve.com/...rain-plug.html