Hi there!
Sorry for the inconvenience.
I have checked your site link, and found out the template is Qubic this time. What have you updated? The framework?
Actually, the Qubic template has not get an update to be compatible with the latest Helix3 version as well as the Joomla 4 too. So if you update the system plugin before the template itself gets a compatibility update, it may cause conflicts in many areas. Kindly roll back to your last working back up version of the site, and do not update the system plugin before the template gets updated.
Have a nice day!
Best Regards