How did you downgrade despite the error in the reconfigure?
sudo apt install gitlab-ee=14.4.0-ee.0
...
Malformed configuration JSON file found at /opt/gitlab/embedded/nodes/gitlab.json.
This usually happens when your last run of `gitlab-ctl reconfigure` didn't complete successfully.
This file is used to check if any of the unsupported configurations are enabled,
and hence require a working reconfigure before upgrading.
Please run `sudo gitlab-ctl reconfigure` to fix it and try again.
Edit:
Thank you _lumy !
That was a hell of a lot more work than I thought, but: Version: 14.4.0-ee 
sudo mv /opt/gitlab/embedded/nodes/gitlab.json /opt/gitlab/embedded/nodes/gitlab.json.conflict
sudo apt install gitlab-ee=14.4.0-ee.0
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,events,id,'[["id"]\, ["id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,ci_builds,id,'[["id"\, "stage_id"]\, ["id_convert_to_bigint"\, "stage_id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,ci_job_artifacts,id,'[["id"\, "job_id"]\, ["id_convert_to_bigint"\, "job_id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,ci_stages,id,'[["id"]\, ["id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,ci_builds_metadata,id,'[["id"]\, ["id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,ci_builds_metadata,id,'[["build_id"]\, ["build_id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,push_event_payloads,event_id,'[["event_id"]\, ["event_id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,deployments,id,'[["deployable_id"]\, ["deployable_id_convert_to_bigint"]]']
sudo gitlab-rake gitlab:background_migrations:finalize[CopyColumnUsingBackgroundMigrationJob,taggings,id,'[["id"\, "taggable_id"]\, ["id_convert_to_bigint"\, "taggable_id_convert_to_bigint"]]']
sudo gitlab-ctl reconfigure
sudo gitlab-ctl restart
# wait
sudo gitlab-ctl status
sudo gitlab-rake gitlab:check
sudo gitlab-rake gitlab:env:info