How to use "cdn_cache_id" in the custom response header?

In the docs, I see that "cdn_cache_id" can be used as a header value, but I received an "Invalid header value" error when using it. I tried to apply it using Cloud Shell and UI, but it's the same. Can anyone confirm what really happened here?

Solution

As it was mentioned by @elithrar at the comment section, this issue was reported and Google Engineers are aware of this issue.

You can keep track of the issue report status by following this thread at Google Public Issue Tracker.

EDIT This is now fixed, and the input field validation now (correctly) accepts {cdn_cache_id} in Console: