Hi,
There is a compatibility issue in some of our themes, including Anima, that affects the availability of the Customize screen with WordPress 6.0.
We are working on updating all our themes that are affected by this issue, but some of them will take a bit longer than others because they are more out of sync with the main codebase we work with.
In the meantime, a workaround to the issue is to check and ensure that your site has no empty categories. If you do not use posts on the site, ensure that at least one (empty) post is assigned to the non-deletable Uncategorised category.