Everything was working fine and Omniauth has stopped working suddenly. I didn't make any code changes.
I checked Twitter Apps Settings: I have callback url to my main production url, and Callback URL Locked to No. All keys are correct.
Any idea? 🤔
Now on twitter callback URL, you must have to add 2 callback URLs and the callback URL must be the path of your application.
I had faced the same problem, now on adding the 2nd callback URL, it's fixed.