How come the Cartwheel App for Target is Not Free anymore (If you already have installed & got it for free, please ignore)

So I have the Cartelwheel app for my phone and I have an iPhone SE (one of the earlier models because I prefer small over bigger sized). And I got the app for Free.

So when I try to get it for my mom's phone, she has an iPhone 6 or 6S, it shows that it costs money because in the App Store, it says: "Get" and when I click on that, it's asking to verify the account before making a purchase & after clicking "Get," the only 2 options I get w/the pop-up: "Cancel" or "Buy."

For my phone, I'll see a little cloud with a down arrow meaning Install & that's how I know that the particular app I want is indeed Free. But the same thing happens for me where if there's an app I'm interested in & it says get, the only options there are: "cancel or buy."

I remember Target's Cartwheel app has been Free for a really long time, so how come the app isn't Free anymore when trying to download/install? In terms of apps, I thought all iPhones were the same, but I guess not.

It is free. The App Store needs you to verify your payment information every so often for security reasons, even if the app doesn't cost anything.