Fatal error after update to PHP 8.0

[preadored]

Hi, we just updated our staging site to PHP 8.0 as our host will require it in a couple of weeks. After the upgrade whenever we try to add a product or new blog post we get the following Fatal Error:

Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 20480 bytes) in /www/xxxxxx/public/wp-includes/meta.php on line 1189

I proceeded to disable plugins to locate the cause and the error disappeared when I disabled Customizer Search. It s not possible to increase our memory with the host, we are already at the limit. Is there another solution for this, please? Our theme is Riode and it states that the plugin is required.

Thank you for any help you can provide.