422 error ActionController::InvalidAuthenticityToken when creating new folders via UI in a folder called "uploads"

Summary

In a project, creating a new folder via the web UI inside a folder called "uploads"

Fails with "422 The change you requested was rejected."

Steps to reproduce

Create a new folder in the docs/uploads test project.

Example Project

https://gitlab.com/tormedo/test_upload_bug

Relevant logs and/or screenshots

Logs on our local instance:

==> /var/log/gitlab/gitlab-rails/production.log <==
Started POST "/example/wiki/-/create_dir/master/docs/uploads/authorize" for xxx.xxx.xxx.xxx at 2020-07-21 11:43:54 +0200
Processing by Projects::TreeController#create_dir as HTML
  Parameters: {"namespace_id"=>"example", "project_id"=>"wiki", "id"=>"master/docs/uploads/authorize"}
Can't verify CSRF token authenticity.
Completed 422 Unprocessable Entity in 4ms (ActiveRecord: 0.0ms | Elasticsearch: 0.0ms | Allocations: 1556)

==> /var/log/gitlab/gitlab-rails/production_json.log <==
{"method":"POST","path":"/example/wiki/-/create_dir/master/docs/uploads/authorize","format":"html","controller":"Projects::TreeController","action":"create_dir","status":422,"time":"2020-07-21T09:43:54.878Z","params":[{"key":"namespace_id","value":"example"},{"key":"project_id","value":"wiki"},{"key":"id","value":"master/docs/uploads/authorize"}],"remote_ip":"xxx.xxx.xxx.xxx","user_id":1,"username":"JhonDoe","ua":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0","redis_calls":1,"redis_duration_s":0.000151,"redis_read_bytes":385,"redis_write_bytes":589,"redis_shared_state_calls":1,"redis_shared_state_duration_s":0.000151,"redis_shared_state_read_bytes":385,"redis_shared_state_write_bytes":589,"correlation_id":"8480e9a1-408e-4287-b555-xxxxxxxxxxx","cpu_s":0.02,"exception.class":"ActionController::InvalidAuthenticityToken","exception.message":"ActionController::InvalidAuthenticityToken","exception.backtrace":[],"db_duration_s":0.0,"view_duration_s":0.0,"duration_s":0.00451}

Output of checks

This bug happens on GitLab.com

Results of GitLab environment info

This bug happens on GitLab.com

Results of GitLab application Check

This bug happens on GitLab.com