I subscribe to the Japanese spotify service. I am subscribed to a paid premium plan. The free period has already ended and I am paying for the service. There are no ads between songs, but very rarely ads are shown when the IOS app is launched. Was there an explanation for this in the help? I contacted support and they replied that it is a campaign and not an advertisement. In the description of the difference between the free and paid plans, it only says that the premium plan is ad-free music.