This is on Drupal 9.3.2 and Civi 5.45.1. To replicate, configure CMS User to not create the user automatically. Fire the rule via cv (e.g. cv api Job.cmsuser).
The login URL is missing the domain, so instead of https://example.org/user/reset/224/1642118358/zaehDxtabytkWHRyLRZwseLxLqYBJunNnvyZlPyDhdo I get /user/reset/224/1642118358/zaehDxtabytkWHRyLRZwseLxLqYBJunNnvyZlPyDhdo.
This does NOT happen if I fire the rule from within the Civi UI, so I'm guessing that Drupal isn't being explicitly bootstrapped.