Even if the Age Verification option from the Ultimate GDPR & CCPA plugin is active users still might try to access the page bypassing this option.
To fully prevent it, please make sure to choose a page for the Select ‘my account’ page.
This will fully block users from trying to browse the website without age confirmation, instead it will be directed to a chosen page.
The option is available in the WordPress dashboard on path Ultimate GDPR & CCPA > Age Verification > Options