Lost purchased songs after iOS 8.4

On the morning before updating to iOS 8.4, all my songs (downloaded and purchased via iTunes) were all synced and good to go, both on my iPhone 6 and iPad Air 2. Right after updating, I went to experience the new Music app when I noticed all my purchased songs (except the one I've bought the day after the update) were nowhere to be found. Tried to search for song name, artist, album and got no results for all my previously purchased songs. All of my downloaded ones were ther also.

I went to my iTunes on my Mac to check if the songs were still there and they were, all of them. Tried to sync both my iPhone and iPad again and got nothing new. Yes, all the purchased songs were checked for syncing. So I decided to search for all my previously purchased content to see if I could buy or download it again from the cloud, but I couldn't. The button were unable for actions, like I already bought it and it were already synced with my device, even though it wasn't that way. On my "Purchased" smart list, the only song list was the one I bought the day before too. Anyone else experienced the same issue?