TYPO3 Core

I want to use a hook for a slug field via "postModifiers" (see feature https://docs.typo3.org/c/typo3/cms-core/master/en-us/Changelog/9.5.x/Feature-88198-TCA-basedSlugModifiersForExtensions.html).
Documentation says:

The method then receives a parameter array with the following values:
'record' ... the full record to be used

But the array key "record" doesn't contain the full record, just some:

array(5) { ["myrecord"]=> string(0) "" ["mytitle"]=> string(4) "test" ["uid"]=> int(199) ["pid"]=> int(175) ["sys_language_uid"]=> int(0) } 

It just contains two custom fields, I think because I provide these fields in the TCA configuration:

'generatorOptions' => [
  'fields' => ['myrecord', 'mytitle'],

Second bug: Field "myrecord" contains no value, even though I chose a record. Configuration for this field:

'config' => array(
  'type' => 'group',
  'internal_type' => 'db',
  'allowed' => 'tx_myext_domain_model_mymodel',

Edit 15.08.2022: Checked with newest TYPO3 v10, bug still existing.