We have been experiencing an intermitten issue when using Oauth for the Authorize.net API over several months. We have many customers using different merchant accounts that we handle API request on behalf of. It appears that every now and then, one or more specific user accounts cannot authenticate using Oauth all of a sudden and the problem often continues for several days before seemingly going away.
We are following all of the steps shown on https://developer.authorize.net/api/reference/features/oauth.html. The problem appears to be happening when redirecting from our site to "https://access.authorize.net/oauth/v1/token" as noted in the documentation, I think typically for the refresh_token exhanges. This results in a 404 response from Authorize.net that isn't documented. Trying to go to the URL directly appears to respond fine. It appears when the error happen for specific customers when they try to continue to the Authorize.net URL above.
We have been seeing this issue intermittently for a while, and didn't even realize it for a long time until a customer alerted us they were routinely getting the error. It appears to come in waves and usually affects one or a few specific customers' merchant accounts over a period of a few days.
We are a Partner and have contacted Authorize.net's support regarding this but have not received a response. Shortly after we sent in a support request several weeks ago, the problem appeared to stop completely so we didn't see any 404s for several weeks until recently again.
We are looking to potentially just add an extra error case if a 404 happens when forwarding users to request a token to prompt them to contact Authorize.net to hopefully add exposure to the problem, and since it appears to be "randomly" isolated to specific Authorize.net accounts. We have just been reluctant to do so since the documentation doesn't show that a 404 should even be possible and it doesn't appear to be a case of the URL being completely inaccessible. We have suspected that it may be due to intermitten load balancing or network issues on Authorize.net's end which maybe clear up after several days.
I searched the forums and other sites and couldn't find anyone else reporting this exact issue. Has anyone run into this or have a suggestion?