Ipad Air2, Djay Pro, decks 3 and 4 do not play in background if you switch apps … Decks 1 and 2 do play in background. Very embarassing to discover this mid set.
PS … I’m not writing this to get a response from Algoriddm … I know they do not care and I dont expect they will solve it or comment on it … I am writing this as a warning to anyone else so they may avoid the problem.