Hello!
I’m having an issue with the authorization code grant flow dropping parameters on login.
When the user is already logged in to Twitch in the browser, it all works correctly.
However if the user is not logged in, after the login the url only contains the claims and every other parameter is lost.
I believe this started happening in the last month or so, with no change on my side.
I’ve tried to reduce the length of the nonce and state to check if I was hitting a max length limit, with no luck.
Here is a sample request (added new lines for readability)
https://id.twitch.tv/oauth2/authorize
?response_type=code
&client_id=<REDACTED>
&redirect_uri=https%3a%2f%2f<REDACTED>%2ftwitch-signin-oidc
&scope=openid+user%3aread%3asubscriptions
&claims=%7b%22userinfo%22%3a%7b%22picture%22%3anull%2c+%22preferred_username%22%3anull%7d%7d
&nonce=cnhW93Je7centKMGCLZAfi9BrO%2fUdx6Ott%2bPiPDAw5%2bSCOG1Y57SFen3XwuDz3TwauBojvIurK6FYpxjwkXeow%3d%3d
&state=cnhW93Je7centKMGCLZAfi9BrO%2fUdx6Ott%2bPiPDAw5%2bSCOG1Y57SFen3XwuDz3TwauBojvIurK6FYpxjwkXeow%3d%3d
and here is the url after the Twitch login prompt
https://id.twitch.tv/oauth2/authorize?claims=%7B%22userinfo%22:%7B%22picture%22:null,%20%22preferred_username%22:null%7D%7D
Any suggestion is welcome 
Thank you!