Error message customization with client level theme

I want a customized error message when client is disabled.
Below is the theme configuration.

clientDisabledMessage=My custom message

It works when theme is set on realm level:

Realm settings > Themes > Login theme: my-custom-theme

But it is not working when theme is set on client level:

Clients > my-client > Settings > Login settings > Login theme: my-custom-theme

Is it expected? Do I miss something?
Can someone please advise me how to overcome this issue (how customized error messages based on client)?

Used version: v22.0.5