TYPO3 Core

I have in my domain model

        'slug' => [
            'label' => 'LLL:EXT:core/Resources/Private/Language/locallang_tca.xlf:pages.slug',
            'exclude' => 1,
            'config' => [
                'type' => 'slug',
                'generatorOptions' => [
                    'fields' => ['subject'],
                    'fieldSeparator' => '/',
                    'prefixParentPageSlug' => false,
                ],
                'fallbackCharacter' => '-',
                'eval' => 'uniqueInSite',
            ],
        ],

When creating a record in 9.5.0 backend the slug field gets auto filled. Also the 'Recalculate URL segment from page title' refresh button does not work anymore to (re)generate the segment.

In 9.5.1 it does not work.

Another question (of topic sry) how can I generate a slug in a domain model of controller for example during a createAction?