Subscription doesnt work – Boom: Bass Booster & Equalizer Review

I just paid for the subscription but the effects are still locked. It keeps wanting me to subscribe again. When I tap the subscribe button, a pop up apple message says: “You are currently subscribed to this”, and it even lets me manage the subscription. But then when I press ‘OK’ instead of ‘manage’, I get another pop up message that says “Purchase did not go through due to an unknown error”.
Review by Bje99 on Boom: Bass Booster & Equalizer.