-34018 SecItemCopyMatching on iOS 13.5

I am seeing the same bug I had 5 years ago, where trying to use the Keychain (SecItemAdd and SecItemCopyMatching specificallY) gives me the dreaded -34018 error.

I used to solve it by adding the Keychain Sharing hack, but now it doesn't work. Possibly as I don't have any other targets in the project, I'm not sure.

Anyone else seen it in newer OS's?
-34018 SecItemCopyMatching on iOS 13.5
 
 
Q