Pagers don't seem to support url fragments.
https://somesite/somepage?someparam=somevalue#somefragment
If creating a url using tokens the fragments get lost somewhere on the way to page reload.
A pager which can keep fragments until the next reload would enable a lot of useful features (like jumping back to a comment, reopening the last selected tab, ...)
Maybe this can help.
code sample of a custom module:
https://www.drupal.org/project/drupal/issues/1293912#comment-13219514
✨
Allow pager to link to #fragments
Needs work
module for links with fragments
https://www.drupal.org/project/menu_link_fragment →
Active
1.0
Code
This module is not a pager, it only adds metadata with page URLs in <head>.
I don't think it would make sense to add fragments to this metadata, but maybe I'm missing something.