Given that you still have the in / out functions, it won't be a blown fuse but, if you want to check it, it's in the rear fuse box ( rear hatch ) and, for a 2015 MY, it should be the number 11 fuse. You could also try disconnecting the negative battery cable for 10 to 15 minutes. This will reset the BCM and may solve the problem. You may have to re-index your windows when you reconnect the battery. If that fails, a trip to an electronics specialist and / or your dealer is probably the next step.
Best of luck
Ross