@KevinTheJedi Hi Kevin, just a small update, I went to the database yesterday and found a couple duplicated entries for the auth. Deleted both entries. Went to osticket then submit the form for oauth again, but the issue persists. I wasn't to sure how to fix that database stuff. I think what I did wrong at the beginning that might cause the issue that I didn't update the plugins when upgrade to 1.17.2.
Anyways, I just set up a new one and able to authenticate with oauth2 with no issue. Everything works now with the new set up and we are happy.
Big thanks to you and your team for this awesome osticket.