Link fields within FlexForm are not resolved

[websi]

Describe the bug The link fields within FlexForm fields not resolved. The value is always "null" in fluid

To Reproduce Steps to reproduce the behavior:

Create an new content element.

name: dkd-customer/quote
typeName: dkdcustomer_quote
group: default
prefixFields: true
prefixType: full
basics:
  - TYPO3/Appearance
fields:
  - identifier: TYPO3/Header
    type: Basic
  - identifier: bodytext
    type: Textarea
    required: true
    enableRichtext: true
    useExistingField: true
  - identifier: pi_flexform
    type: FlexForm
    useExistingField: true
    fields:
      - identifier: author
        type: Text
      - identifier: url
        type: Link
        autocomplete: true
        allowedTypes:
          - page
          - url

Output the content within frontend.html

<f:section name="Main">
    <f:debug title="All">{_all}</f:debug>
    <f:debug title="URL Content Blocks 'data.pi_flexform.url'">{data.pi_flexform.url}</f:debug>
    <f:debug title="URL Content Blocks 'data.pi_flexform.url.url'">{data.pi_flexform.url.url}</f:debug>
<blockquote cite="{f:if(condition: '{data.pi_flexform.url.url}', then: '{f:uri.typolink(parameter: data.pi_flexform.url.url)}')}">
    <f:format.html>{data.bodytext}</f:format.html>
    <f:if condition="{flexFormData.author}"><footer><cite>{flexFormData.author}</cite></footer></f:if>
</blockquote>
</f:section>

Expected behavior The link field should be resolved correctly

Screenshots

The flex-form data provided via

tt_content.dkdcustomer_quote {
  dataProcessing {
    # RecordPropertyClosure are neve resolved
    5 = flex-form
  }
}

TYPO3 Version - 13.4.1

Content Blocks Version: - 1.0.4

Additional context

[nhovratov]

Confirmed bug.

[nhovratov]

This is an issue only in Core. I've created a forge ticket for this: https://forge.typo3.org/issues/105621

[nhovratov]

This is fixed in Core now: https://review.typo3.org/c/Packages/TYPO3.CMS/+/87046

Will be fixed with release of TYPO3 13.4.2