TYPO3 Core

Can you please share the TCA configuration for that particular field?
Maybe it can be reproduced with https://github.com/TYPO3/styleguide as well?

Oh sorry, i forgot the code example.
I can reproduce it with the styleguide extension.
The code is practically identical to the "inline use combination" element.

TCA config of the field (in `Configuration/TCA/tx_styleguide_inline_usecombination.php`)

'inline_1' => [
    'exclude' => 1,
    'label' => 'inline_1',
    'config' => [
        'type' => 'inline',
        'foreign_table' => 'tx_styleguide_inline_usecombination_mm',
        'foreign_field' => 'select_parent',
        'foreign_selector' => 'select_child',
        'foreign_unique' => 'select_child',
        'maxitems' => 9999,
        'autoSizeMax' => 10,
        'appearance' => [
            'newRecordLinkAddTitle' => 1,
            'useCombination' => true,
            'collapseAll' => false,
            'levelLinksPosition' => 'top',
            'showSynchronizationLink' => 1,
            'showPossibleLocalizationRecords' => 1,
            'showAllLocalizationLink' => 1,
        ],
    ],
],