Muito obrigado @Jagster
Encontrei este log do console
Deprecation notice: The icon name "undo" has been updated to "arrow-rotate-left". Please use the new name in your code. Old names will be removed in Q2 2025. [deprecation id: discourse.fontawesome-6-upgrade] [info: https://meta.discourse.org/t/325349]
Mas não tenho certeza de onde atualizar este ícone.