Custom page for IP block at account level

hi,

Using Firewall > Tools you can set an Account wide IP/Country Block restriction.
Also, in Account > Configurations you can set a Custom Page to display instead of the Cloudflare branded response page.

However, it appears that if the setup is as above, the Custom Page set in Configurations is not displayed and the Cloudflare 1009 page is served.

Can somebody confirm this is the expected behavior?

TIA