How to turn off passthrough of basic auth in Cockpit?

I am running Cockpit behing a reverse proxy. No issues there. Then I added basic auth for that location, and it seems that Cockpit tries to login with the user and password that was used for the HTTP basic auth.
I can also see a failed login from ::ffff: on web console.

If I don’t use HTTP basic auth, this does not happen.

So how can I tell cockpit to ignore the HTTP basic auth credentials?

Linux atvie01s 6.2.14-300.fc38.x86_64 #1 SMP PREEMPT_DYNAMIC Mon May 1 00:55:28 UTC 2023 x86_64 GNU/Linux