Apps are forever associated with the Apple ID that was used to buy them. That Apple ID is encoded into the licensed copy that you downloaded. Apple does not merge Apple IDs and Apple does not transfer content from one Apple ID to another. You can NEVER associate the apps bought with the old Apple ID with the new Apple ID. Which is why making a new Apple ID is a bad idea.
You will need to repurchase them with the new Apple iD.
ASC - Late 2012 Mac mini, macOS 10.13.3; Watch, 38 mm AL, watchOS 4.2.2; iPad Air 2 & iPhone 7+, iOS 11.2.5; TV 4th Gen, tvOS 10.2.6; Airport Express