The HTTP 400 Bad Request client error response status code indicates that the server would not process the request due to something the server considered to be a client error.

Any cookie that is set with a size greater than the limit is ignored (and not set).

Most of the browsers have a limit on the size of cookies, check Browser cookie limits for some common browsers. When the total size of cookies exceeds this limit, browsers may reject the request. For example Chrome browser has 180 Cookie count limit per domain Total size of cookies 4096.

The error message Request Header Or Cookie Too Large. One of your headers is very big, and nginx is rejecting it. You are using nginx server, try to increase the buffer value and set it as large_client_header_buffers 4 32k.

Check your Kubernetes ingress annotations to ensure they are correctly applied and that the ingress controller is properly configured to handle large headers.

Refer to this document by Docdevs for more information

Note:

To support most browsers, cookies should not exceed 60 per domain, and total cookie size (across all cookies) should be less than or equal to 4093 bytes.