Token [node:menu-link:root:parents] doesnt work

Token [node:menu-link:root:parents] results in a blank result.
After some debugging I tried [node:menu-link:parents] - without "root". This results in the menu-link names.
But with "-" as delimiter:
Result: "some-colors-red/my-trouser" instead of "some-colors/red/my-trouser"

The "-" is build in token_render_array()

Any Idea ?
(Drupal 8.4.3 Pathauto 8-1.0)