The 'update' button is only available in a specific scoped application table but not available on other OOB tables.
This issue may occur if the Global 'Update' button is being overridden by another 'Update' button from any scoped table from the store app like 'SLM Compliance configuration'.
As a workaround, the override field of the scoped button should be empty. It will bring back the global 'Update' button but even under the scoped table, the global button will appear, the custom/scope specific button will not work.
To resolve this issue permanently, contact the respective store app owner of the plugin.