Editing quota from a project in Horizon is removing users from the project with keystone v3 and multi domains setup

Issue

While editing quota from a project in Horizon , this action is removing users from the project.

We are using Keystone v3 with multi domains setup.

I create a project in "Default" Keystone domain:

# openstack project create test
+-------------+----------------------------------+
| Field       | Value                            |
+-------------+----------------------------------+
| description |                                  |
| domain_id   | default                          |
| enabled     | True                             |
| id          | ceae5812586c4d7e915199c6dd5f4868 |
| is_domain   | False                            |
| name        | test                             |
| parent_id   | None                             |
+-------------+----------------------------------+

I add a user from a different domain (TESTDOM, an LDAP domain) like this:

# openstack role add --project test --user-domain TESTDOM --user domuser2 _member_

I verify the user is properly located in the project:

# openstack user list --project test
+------------------------------------------------------------------+-----------+
| ID                                                               | Name      |
+------------------------------------------------------------------+-----------+
| 13e3a99ae7410be0e41167d3d6fae7dea1b6d0c99362507c5c3b8c26a7b3bc1f | domuser1  |
| e9adb93931a3356afbb817f9c2a17046d1ac9127f1112f9751fdb09efe5046fb | domuser2  |
+------------------------------------------------------------------+-----------+

At this point the user can connect to Horizon with the TESTDOM domain and it's LDAP credential and do actions in OpenStack.

Then I log in the Horizon dashboard by using my account (which is admin) ldap credential and TESTDOM domain.
I go in identity -> Projects -> on test project I do "Edit quota" -> I modify the number of instance from 10 to 15 -> update.

At this point Horizon removed all the users not belonging to the Default domain and that were assigned to this tenant!

# openstack user list --project test

#