URL in link field adds duplicate parameters in query string when using an internal relative path
Seems like a bug in Core at the moment. Follow the issue queue: https://www.drupal.org/project/drupal/issues/2885351

Seems like a workaround currently is to use full paths instead of relative ones or use the patch in the issue above to patch core.

There seems to be a module someone made too since patching core isn't ideal:
https://www.drupal.org/project/link_formatter_query_fix