When `qtawesome` release v1.4.0 they dropped the prefix `fa` as an alias for FontAwesome 4 icons. https://github.com/spyder-ide/qtawesome/issues/279#issuecomment-2689742514
When
qtawesomerelease v1.4.0 they dropped the prefixfaas an alias for FontAwesome 4 icons.spyder-ide/qtawesome#279 (comment)