Can not save the posthog settings form - The used authentication method is not allowed on this route

For now I set the key in config, but this is really strange!

Just ran into the same issue! Really weird!

OK, this only happens in an internal project. And isn't related to the module itself.

I will open an internal ticket.

Nice, thanks @Grevil!

Can we reproduce this with any other form?

Looking for possible reasons, it seems to me that maybe the "host" key in the form is a problem for a contrib module?

We should check with a different key name first.

This won't be the reason, as the issue is not reproducible outside birapa. Also, the access is denied before we even access the submitForm call. Its most likely some access checker module we have enabled.

The key might be a problem for THAT module, if there is one.

Nope, changing the form elements id to something else doesn't fix the issue.