TYPO3 Core

i can confirm this behaviour.

simple example:

i want to set the default targets for 'page' and 'url':

my ckeditor yaml configuration:

buttons:
  link:
    page:
      properties:
        target:
          default: '_self'
    url:
      properties:
        target:
          default: '_blank'

When i select a link and open the link wizard, i have inconsistent behaviour when clicking the page type tabs, see attached screen.

1. i click page, the target is set to _self (this is ok)
2. i click external url, the target ist set to _self (this is wrong)
3. i click mail, the target is left blank (this is ok)
3. i click external url, the target ist set to _blank (this is ok)

the same behaviour in TYPO3 8 and 9

This is a question of the feature definition.

For the title and target:
It should be set once to the default, but should be kept unchanged further on. The assumption is that a user might have entered a custom text that shall not be removed from the machine.

after the ticket is open for so long and without interaction, I consider the explanation given by Markus as sufficient and close the issue.