it comes up with a red banner and an error message every time i try to buy from user shops - however if i actually go into their shop i can buy things, it's just in shop search that it doesn't work. It also stopped working for a bit last night but came back eventually.

Pinging again, just in case the first one got lost!

it only happens off and on, and i'm just questing like usual, so it's not like i'm buying hundreds of items