GitLab Pages: cannot re-add a domain that has been removed recently ("Domain has already been taken" error)

Prerequisites

• create a repo with Pages enabled
• add a custom domain to Pages
• validate that custom domain (_gitlab-pages-verification-code etc)
• make sure it has Automatic certificate management using Let's Encrypt ENABLED

How to reproduce

1. remove domain
2. try to add the same domain again

Actual behaviour: getting error 'Domain has already been taken'

Expected: Should be able to add the domain

This has been raised numerous times on the forum. One example of many: https://forum.gitlab.com/t/gitlab-com-domain-taken-issue/4496

Unfortunately this is preventing me from using GitLab Pages for the next 3 months until the Let's Encrypt cert is invalidated................ :'(