Issue adding members to Teams private channel with Graph API

Hi, I'm provisioning a Microsoft Teams with graph API and have a weird behavior when adding members to a private channel. When I create the private channel I also provide the members list. After the private channel is sucessfully created, if I go into Microsoft Teams, I see the private channel but I do not see the members but only the owner. However, If I go into Teams administration interface, I see the owner and members in the private channel..... Same thing using graph explorer
Also in the SharePoint site, I see the member in the SP member group... Why I'm not seeing the members of the private channel in "manage channel" from Teams client?
Note: "roles": [] is the same as "roles": ['Member']

Create private channel

POST https://graph.microsoft.com/v1.0/teams/57fb72d0-d811-46f4-8947-305e6072eaa5/channels
{
"@odata.type": "#Microsoft.Graph.channel",
"membershipType": "private",
"displayName": "My First Private Channel",
"description": "This is my first private channels",
"members":
[
{
"roles": [],
"user@odata.bind": "https://graph.microsoft.com/v1.0/users('xxxx')",
"@odata.type": "#microsoft.graph.aadUserConversationMember"
},
{
"roles": [
"owner"
],
"user@odata.bind": "https://graph.microsoft.com/v1.0/users('xxxx')",
"@odata.type": "#microsoft.graph.aadUserConversationMember"
}
]
}