List user projects return always empty (Gitlab.com, CE edition, private projects)

Summary

List user projects return always empty. https://docs.gitlab.com/ce/api/projects.html#list-user-projects

I am on Gitlab.com (CE edition). Only private projects are used.

Use case/temporary work around: for now, i have no way to find for an user which project a user is a developper for instance, in one api call, as /users/:user_id/projects don't work like described on this issue. I have with the API to list through all the projects (there are many), and check if the user is a member and developper. So it involves many API call (as many as project!). And so for each user.

Steps to reproduce

Get my numerical ID: https://gitlab.com/api/v4/users?username={my-username}

Log into GitLab with my username/password. Open a new tab with url: https://gitlab.com/api/v4/users/{my-user-numerical-id}/projects

OR

Call with an "api" scope token: https://gitlab.com/api/v4/users/{my-user-numerical-id}/projects?private_token={my-token-at-api-scope)

=> both return an empty ([]) json array.

I can add that calling:

https://gitlab.com/api/v4/projects/{projectid}/users?private_token={my-token-at-api-scope) display well all the users of the project. Taking the id of one of them and calling https://gitlab.com/api/v4/users/{userid}/projects?private_token={my-token-at-api-scope) return empty... but just on the first call it was listed as user of the project, so this project should have been listed in the second api call.

Example Project

Not possible, as all projects are private.

What is the current bug behavior?

Return an empty ([]) json array.

What is the expected correct behavior?

Should return the list of the private projects.

Output of checks

This bug happens on GitLab.com