Hello,
I hope report the right bug with the right Drupal 8 component (Drupal 8.9.1).
I have notice that (some) menu links are not aliased on the homepage. I have lost a lot of time with this bug, but I have found a workaround. Here I explain this bug and the solution I have found temporaly: https://www.drupal.org/forum/support/post-installation/2020-06-20/menu-l...
I hope it helps and sorry if you can not reproduice.
Regards