redirectProxyUrl not possible with PKCE?

[samtgarson]

PKCE functionality seems to leave a cookie (__Secure-next-auth.pkce.code_verifier) which the app relies on to verify the PKCE challenge on the other side of the OAuth redirect.

However, when using the redirectProxyUrl/AUTH_REDIRECT_PROXY_URL functionality, it seems that the PKCE challenge occurs on the stable proxy domain, not the preview domain which is being authenticated?

As the cookie above is created with the preview domain (not the stable proxy domain), the PKCE code verifier is not accessible on the stable domain, and I'm getting an error:

validCheck: PKCE code_verifier cookie was missing. 

Am I setting something up incorrectly or is this a bug?

FWIW I'm authenticating with Google.

[samtgarson]

Seems like this is some kind of configuration issue, unable to recreate on an isolated recreation

[musabash]

Hi, I am getting the same error after I configured everything as explained here.
Have you managed to find a solution for this one?