Sorry to hear about the inconvenience. Kindly, please share your Site WP-ADMIN Login details in the Private Content field so that we can check this concern on your Site and help you out accordingly.
I have checked your site and the categories in the page title are working fine on the mobile device.
See video for clarification: https://uploadnow.io/f/BSlDfXb
Check back your site after completely clearing the browser cache and check the issue.