A friend of mine has an issue with his SX2 after doing some updates. He updated from Yosemite to High Sierra and from Serato DJ 1.9.7 to Serato DJ Pro. After doing these updates he now has to open up his Sound preferences in High Sierra in order for the SX2 to function. If he doesn't do that then when he connects the SX2 he only see the virtual decks but he is not able to play using the controller or by clicking on the play button within the software. He can scroll through his library and load songs to the decks but they won't play unless he opens the Sound preferences. He doesn't have to do anything within the sound preferences. He just has to open that window. Same thing happens with his SB2. He has a second computer and this doesn't happen on that computer.

Seems like this is an issue with his OS and not the controller since it worked fine until he did all of those updates and since the controllers work on other computers with no issue.

It's almost as if the OS doesn't know to switch sound cards until the sound preferences are opened.

Any ideas what the issue could be?