Plaid does not support connections between [Bank] and [Application] - plaid

Question

I'm using Plaid Link and server-side API to let users register account/routing numbers with the auth product. We have customers with a bank that's retrievable in the UI's Select Your Bank search bar and with the API's /institutions/get endpoint, but it seems to not be a viable option to select and link. When I try to link it in the UI, there's a warning icon and a message that says "Plaid does not support connections between [Bank] and [Application]. Try another financial institution or check for another connection method."
Does this mean the bank can be supported, but my application isn't properly configured to support it? It seems to have the product I'm using (auth). I'd like to enable customers to add this specific bank, but also understand what the blockers are to supporting similar banks for my application.
I had seen that some banks require Oauth, but this one doesn't look like it does (oauth is false for it when I call /institutions/get). I wonder if there's some other requirement I'm missing.

Answer 1

You say you're initializing with auth, but are you initializing with only auth and nothing else? You can get this error if you're initializing with multiple products and it doesn't support all of them.
What's the bank? Knowing that would help a lot for troubleshooting; some banks are special snowflakes in various ways.

Answer 2

Try (Node API)
PlaidClient.institutionsGetById(institutionId);
which will give you the products the given institution supports.
Example:
{"country_codes":["US"],"institution_id":"ins_xxx","name":"XYZ","oauth":false,"products":["assets","balance","transactions","identity"],"routing_numbers":["xxx"]}
If you have generated a link token that does not contain the products listed from your bank (above), you will get the error "Plaid does not support connections between ..."