Upgrade to 8.16.3 dissapear Group Avatars

Summary

A customer upgraded to 8.16.3 and their Private Group Avatars disappeared. All other avatars including users and public groups are still fine.

Relevant logs and/or screenshots

Results of GitLab environment info

sudo gitlab-rake gitlab:env:info

System information 
System: 
Current User: git 
Using RVM: no 
Ruby Version: 2.3.3p222 
Gem Version: 2.6.6 
Bundler Version:1.13.7 
Rake Version: 10.5.0 
Sidekiq Version:4.2.7

GitLab information 
Version: 8.16.3-ee 
Revision: bc46393 
Directory: /opt/gitlab/embedded/service/gitlab-rails 
DB Adapter: PostgreSQL 
DB Version: 9.2.18 
URL: http://atap-gitlab.spar.local.at 
HTTP Clone URL: http://atap-gitlab.spar.local.at/some-group/some-project.git 
SSH Clone URL: git@atap-gitlab.spar.local.at:some-group/some-project.git 
Elasticsearch: no 
Geo: no 
Using LDAP: yes 
Using Omniauth: no

GitLab Shell 
Version: 4.1.1 
Repository storage paths: 
- default: /opt/gitlab/git-data/repositories 
Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks/ 
Git: /opt/gitlab/embedded/bin/git

I don't know why in the GitLab information section Elasticsearch is set to "no". In the Gitlab Admin Ovierview Tab the Feature Elasticsearch has a green dot and seems to be enabled. But I don't think this is related to the Group Icon Issue.

A customer reported it here: https://gitlab.zendesk.com/agent/tickets/62938