Upgrade 12.10.14 to14.X - PG::UniqueViolation: ERROR

Hello,

I am upgrating gitlab CE from 12.10.14 to latest 14 version.

Upgrades paths go fine until the step 14.0.12 to 14.8.5.

In the gitlab reconfigure, after 14.8.5 is installed i get this error:

There was an error running gitlab-ctl reconfigure:

rails_migration[gitlab-rails] (gitlab::database_migrations line 51) had an error: Mixlib::ShellOut::ShellCommandFailed: bash[migrate gitlab-rails database] (/opt/gitlab/embedded/cookbooks/cache/cookbooks/gitlab/resources/rails_migration.rb line 16) had an error: Mixlib::ShellOut::ShellCommandFailed: Expected process to exit with [0], but received '1'
---- Begin output of "bash"  "/tmp/chef-script20220331-961221-3uq2ke" ----
STDOUT: rake aborted!
StandardError: An error has occurred, all later migrations canceled:

PG::UniqueViolation: ERROR:  could not create unique index "index_events_on_id_convert_to_bigint"
DETAIL:  Key (id_convert_to_bigint)=(15226) is duplicated.
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:166:in `block in add_concurrent_index'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:387:in `disable_statement_timeout'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:165:in `add_concurrent_index'
/opt/gitlab/embedded/service/gitlab-rails/db/post_migrate/20210622045705_finalize_events_bigint_conversion.rb:29:in `swap'
/opt/gitlab/embedded/service/gitlab-rails/db/post_migrate/20210622045705_finalize_events_bigint_conversion.rb:18:in `up'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migrations/lock_retry_mixin.rb:36:in `ddl_transaction'
/opt/gitlab/embedded/service/gitlab-rails/lib/tasks/gitlab/db.rake:72:in `block (3 levels) in <top (required)>'
/opt/gitlab/embedded/bin/bundle:23:in `load'
/opt/gitlab/embedded/bin/bundle:23:in `<main>'

Caused by:
ActiveRecord::RecordNotUnique: PG::UniqueViolation: ERROR:  could not create unique index "index_events_on_id_convert_to_bigint"
DETAIL:  Key (id_convert_to_bigint)=(15226) is duplicated.
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:166:in `block in add_concurrent_index'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:387:in `disable_statement_timeout'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:165:in `add_concurrent_index'
/opt/gitlab/embedded/service/gitlab-rails/db/post_migrate/20210622045705_finalize_events_bigint_conversion.rb:29:in `swap'
/opt/gitlab/embedded/service/gitlab-rails/db/post_migrate/20210622045705_finalize_events_bigint_conversion.rb:18:in `up'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migrations/lock_retry_mixin.rb:36:in `ddl_transaction'
/opt/gitlab/embedded/service/gitlab-rails/lib/tasks/gitlab/db.rake:72:in `block (3 levels) in <top (required)>'
/opt/gitlab/embedded/bin/bundle:23:in `load'
/opt/gitlab/embedded/bin/bundle:23:in `<main>'

Caused by:
PG::UniqueViolation: ERROR:  could not create unique index "index_events_on_id_convert_to_bigint"
DETAIL:  Key (id_convert_to_bigint)=(15226) is duplicated.
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:166:in `block in add_concurrent_index'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:387:in `disable_statement_timeout'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migration_helpers.rb:165:in `add_concurrent_index'
/opt/gitlab/embedded/service/gitlab-rails/db/post_migrate/20210622045705_finalize_events_bigint_conversion.rb:29:in `swap'
/opt/gitlab/embedded/service/gitlab-rails/db/post_migrate/20210622045705_finalize_events_bigint_conversion.rb:18:in `up'
/opt/gitlab/embedded/service/gitlab-rails/lib/gitlab/database/migrations/lock_retry_mixin.rb:36:in `ddl_transaction'
/opt/gitlab/embedded/service/gitlab-rails/lib/tasks/gitlab/db.rake:72:in `block (3 levels) in <top (required)>'
/opt/gitlab/embedded/bin/bundle:23:in `load'
/opt/gitlab/embedded/bin/bundle:23:in `<main>'
Tasks: TOP => db:migrate

Any thoughts how to solve this problem ?

Tks,