There's something wrong with your site then. Bootstrap 5 isn't loading maybe. The below is what CB and Joomla login modules will look like on a clean Joomla 4 install with Cassiopeia.
CB Login Module
Joomla Login Module
Sorry, there's nothing more I can do for you. This doesn't appear to be a CB problem, but an issue with your site itself. I cannot help you any further without an active professional, developer, or business subscription as the next step would be reviewing your install.