Multi-instance migration failed when adding a new instance

[twofoursixeight]

I don’t have the best idea on this subject, but I could try to help.
This topic is related:

Migration failed upgrading to latest from ~3 weeks ago

1 migrations failed! Failed to migrate default #<StandardError: An error has occurred, all later migrations canceled: PG::UniqueViolation: ERROR: duplicate key value violates unique constraint "index_user_emails_on_email" DETAIL: Key (lower(email::text))=(talk@remobjects.com<mailto:talk@remobjects.com) already exists. > /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/rack-mini-profiler-2.3.3/lib/patches/db/pg.rb:110:in `exec' /var/www/discourse/vendor/bundle/ruby/2.7.0/gems/rack-mini-profil…