Are the shops broken?

The starter for this question. Ever since the Absolutely Savage album released I decided I was gonna finish it. I love those variants and the rewards are great! I had been saving Gold (I'm FreeToPlay) for when I found an album I looked so I had enough saved to get 6 variants. Ever since then I haven't seen a single Alex Horley, 1,000,000 BC or Savage Land variant since! I've seen all the PANDart variants 4 times over and the same Sweeney Boo rogue 6 times now. Is this an uncommon experience or is it time to make the shop rotate though all variants before you see a repeat?

TL;DR the shop feels broken and stuck in a loop where I never see the variants I'd like to buy.