Keycloak 15.02 - User Groups Deleted

Hello,

When using the Keycloak API to update a user, somehow the user groups are deleted.
Is it any way to investigate what kind of request the server received?
Is that even possible ?

This a sample of the request that I sent to update a user, but even if the group list is empty the user groups are not updated.

curl -vvv -X PUT -H "Authorization: Bearer $TKN" \ -H 'Accept: application/json' \ -H 'Content-Type: application/json' \ -d '{ "id": "20395f56-fc80-4481-87bc-e3d4998b3066", "createdTimestamp": 1697634494546, "username": "mcdusercontroller_c50a6c", "enabled": true, "totp": false, "emailVerified": false, "lastName": "lastName empty group array", "email": "mcdusercontroller_c50a6c@sample.com", "attributes": { "locale": ["ja"] }, "disableableCredentialTypes": [], "requiredActions": ["UPDATE_PASSWORD"], "notBefore": 0, "access": { "manageGroupMembership": true, "view": true, "mapRoles": true, "impersonate": true, "manage": true }, "groups": []}' \ "${SRV}/auth/admin/realms/${TENANT}/users/20395f56-fc80-4481-87bc-e3d4998b3066"

Thank you.