On v. 5.9.7, the duplicate and delete buttons for custom fields are not functioning. It appears that the class og-item was given a position: relative in 5.9.7 whereas in 5.9.5 it didn't have that positioning and the buttons worked properly. Please see my video below for demo:
What is the WordPress version on your site? Please update WP to the new version 6.5.2, deactivate all plugins except Meta Box, MB extension plugins, switch to a WordPress theme and check the issue again.
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