Bug in base domain matching?

Hi,

For base domain matching, the help (https://bitwarden.com/help/article/uri-match-detection/) says that:
https://www.google.com will match https://sub.accounts.google.com

However,
https://gc.ca does not match https://cms-sgj.cra-arc.gc.ca/gol-ged/awsc/cms/login

while https://cra-arc.gc.ca does match.

Am I missing something or is the base domain matching not working as advertised?

Cheers E