My short response to all this Showdown stuff....
I never have had issues with it. Until yesterday.
I was oddly enough on my PC and Mobile and I was checking the credits/surveys section on the Mobile side while I was searching for an Opponent in the Showdown.
While I stopped the search on my PC for that next Opponent, I seen that the search did not shut down on my Mobile.
I caught this quickly and was able to get out of searching and close my Mobile and resume on my PC. So no bogeys for me.
Moral of my story...
Don't use PC and Mobile at the same time with both Apps going maybe. I know I won't do that again in a Showdown.