Why is everything saying "Not available in your region"?

So I was looking on mercari and was gonna buy a cool looking item of a character and it said it is listed like 2 states away from me and I go to but it and it says "not available in your region". I'm like that's strange then shrug it off and go to buy something else and that item also says " not available in your region" that item being a bit further away in California (it's like a little keychain nothing too crazy either since I've bought stuff like this before off mercari)

Everywhere online says something about glitches or using a VPN, but I don't have any kind of VPN, and if its a glitch how exactly do I fix said glitch? Am I just sorta screwed until the app eventually gets an update to fix it or is there some sort of work around?