Hey there @magwas and welcome to the Auth0 Community!
I’m happy to assist you with the challenge you are facing. To start, can you get us a HAR file of the broken authentication workflow that you are experiencing and direct message that over to me along with your tenant name? Please be sure to select “Preserve log” to catch redirects and scrub the file of user passwords before passing, thanks!
When diving into your HAR file I am not seeing the id come across during 404 Github exchange. Can you take a look at that during your exchange? Thanks in advance!
After looking at it with a senior engineer on our support team it appears everything is running successfully for the authentication with Auth0 as displayed in the HAR file. However there does to be something going on with Github during this flow. Is there multiple tabs open to Github/login when this occurs?
Let’s give this another look with a minimal setup running in your browser. Snag another HAR file with the “Preserve log” enabled to catch redirects and send it over in a direct message. If you are using Chrome during this instance can you also message the extensions you have enabled as well. Please detail the workflow and I will give this another look to verify with our team. Thanks @magwas.
I wanted to follow up @magwas, after reviewing your latest HAR file capture with one of our senior support engineers. After more further investigation we were able to reproduce the error you experienced and it appears to be related to your Github Client ID is invalid. I would recommend taking a look at this and verifying you have the correct corresponding data in you dashboard’s connections. I have linked documentation related to this subject below as well. Please let me know if this helps you in your pursuit. Thank you.