edX forum mongodb authentication

Looks like it broke something, as reported in github.
Now local quickstart is failing the forum-job:

Creating tutor_local_forum-job_run ... done
Waiting for mongodb/elasticsearch...
2021/09/17 14:12:34 Waiting for: tcp://mongodb:27017
2021/09/17 14:12:34 Waiting for: http://elasticsearch:9200
2021/09/17 14:12:34 Received 200 from http://elasticsearch:9200
2021/09/17 14:12:34 Connected to tcp://mongodb:27017
/openedx/cs_comments_service/lib/tasks/db.rake:28: warning: already initialized constant COURSE_ID
/openedx/cs_comments_service/models/constants.rb:2: warning: previous definition of COURSE_ID was here
/openedx/cs_comments_service/lib/tasks/kpis.rake:7: warning: already initialized constant ROOT
/openedx/cs_comments_service/lib/tasks/deep_search.rake:7: warning: previous definition of ROOT was here
/openedx/cs_comments_service/lib/tasks/flags.rake:6: warning: already initialized constant ROOT
/openedx/cs_comments_service/lib/tasks/kpis.rake:7: warning: previous definition of ROOT was here
W, [2021-09-17T14:12:40.285471 #13]  WARN -- : Overwriting existing field _id in class User.
W, [2021-09-17T14:12:40.395846 #13]  WARN -- : MONGODB | Unsupported client option 'max_retries'. It will be ignored.
W, [2021-09-17T14:12:40.395983 #13]  WARN -- : MONGODB | Unsupported client option 'retry_interval'. It will be ignored.
W, [2021-09-17T14:12:40.396101 #13]  WARN -- : MONGODB | Unsupported client option 'timeout'. It will be ignored.
rake aborted!
NoMethodError: undefined method `encode' for nil:NilClass
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/auth/user.rb:87:in `encoded_name'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/auth/scram/conversation.rb:320:in `first_bare'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/auth/scram/conversation.rb:263:in `client_first_message'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/auth/scram/conversation.rb:181:in `start'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/auth/scram.rb:58:in `login'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection.rb:249:in `block in authenticate!'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server.rb:267:in `handle_auth_failure!'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection.rb:248:in `authenticate!'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection.rb:100:in `connect!'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connectable.rb:84:in `ensure_connected'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection.rb:270:in `write'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection.rb:229:in `deliver'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection.rb:144:in `block in dispatch'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/monitoring/publishable.rb:47:in `publish_command'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection.rb:143:in `dispatch'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/operation/shared/executable.rb:33:in `block in dispatch_message'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server/connection_pool.rb:110:in `with_connection'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/server.rb:251:in `with_connection'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/operation/shared/executable.rb:32:in `dispatch_message'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/operation/find/op_msg.rb:46:in `execute'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/operation/find.rb:43:in `execute'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/collection/view/iterable.rb:82:in `send_initial_query'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/collection/view/iterable.rb:42:in `block in each'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/retryable.rb:44:in `read_with_retry'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongo-2.5.3/lib/mongo/collection/view/iterable.rb:40:in `each'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/mongoid-7.0.5/lib/mongoid/query_cache.rb:227:in `each'
/openedx/cs_comments_service/app.rb:173:in `map'
/openedx/cs_comments_service/app.rb:173:in `<top (required)>'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/activesupport-6.0.2.1/lib/active_support/dependencies.rb:325:in `require'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/activesupport-6.0.2.1/lib/active_support/dependencies.rb:325:in `block in require'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/activesupport-6.0.2.1/lib/active_support/dependencies.rb:291:in `load_dependency'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/activesupport-6.0.2.1/lib/active_support/dependencies.rb:325:in `require'
/openedx/cs_comments_service/Rakefile:24:in `block in <top (required)>'
/openedx/cs_comments_service/vendor/bundle/ruby/2.5.0/gems/rake-12.0.0/exe/rake:27:in `<top (required)>'
/openedx/ruby/bin/bundle:23:in `load'
/openedx/ruby/bin/bundle:23:in `<main>'
Tasks: TOP => search:initialize => environment
(See full trace by running task with --trace)
ERROR: 1
Error: Command failed with status 1: docker-compose -f /Users/andres/Workspace/tutor-test/env/local/docker-compose.yml -f /Users/andres/Workspace/tutor-test/env/local/docker-compose.prod.yml --project-name tutor_local -f /Users/andres/Workspace/tutor-test/env/local/docker-compose.jobs.yml run --rm forum-job sh -e -c bundle exec rake search:initialize
bundle exec rake search:rebuild_indices