OAuth 2.0 Authorization Code flow with PKCE not working correct

[LucaFilitz]

Hello,
I just implemented an OAuth 2.0 Authorization Code flow to log in users to their solid pod. While doing this, I registered my client at solidcommunity.net. Then, while implementing, I noticed that the PKCE plugin for the Auth Code flow is not working correctly.
When you request the auth code and pass on the challenge, everything is fine. You get the code. But when you try to get an access token from the code, it works without the verifier. Basically you pass the challenge for no reason.
Am I doing something wrong here? Is this excpected behavior?

Kind regards
Luca