Simple. When you view your shop or go to "Your Shops", the amounts for "Lifetime Items Sold" and "Lifetime sP Made" has reset to 0.

Even when you sell something, the number does not go back up. I was at 350,000,000+ sP sold, and now it says 0. I have 30,000 in my profits, and still shows 0.

I've checked quite a few other shops from other users, and the issue is present for them as well.