[Bug]: Adding member into circle does not add them to circle's discussion when circle option "members must accept invitation" is activated

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Hello,

When you add a member into a circle, and this circle have an already existing discussion, the member is added to this discussion.

But when you enable "Member must accept invitation" on the circle settings, when the member accept the invitation, he is not included into the circle discussion.
When this option "Member must accept invitation" is not enabled, when you add a member to the circle, this member is correctly added to the discussion.

Steps to reproduce

1. Create circle
2. Create discussion
3. add circle into the discussion
4. Set the circle to "member must accept invitation"
5. Add a member to the circle
6. This member accept the invitation
7. This member is not added to the discussion

Expected behavior

Member of the circle that accepted the circle invitation should be added to the circle's discussions.

Installation method

Community Manual installation with Archive

Nextcloud Server version

28

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.1

Web server

Nginx

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "192.168.122.195",
            "***REMOVED SENSITIVE VALUE***"
        ],
        "maintenance_window_start": 1,
        "quota_include_external_storage": true,
        "skeletondirectory": "\/var\/www\/box-ng\/core\/skeleton\/skeleton-",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "tempdirectory": "\/BOX-NG\/tmp",
        "cache_path": "\/BOX-NG\/cache",
        "cache_chunk_gc_ttl": 86400,
        "auto_logout": false,
        "session_lifetime": 7200,
        "remember_login_cookie_lifetime": 864000,
        "session_keepalive": true,
        "dbtype": "mysql",
        "version": "28.0.3.2",
        "overwrite.cli.url": "***REMOVED SENSITIVE VALUE***",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "proxy": "***REMOVED SENSITIVE VALUE***",
        "loglevel": 0,
        "logfile": "\/var\/log\/box-ng\/appli-box-ng.log",
        "log_rotate_size": 524288000,
        "updater.release.channel": "stable",
        "trashbin_retention_obligation": "30,60",
        "versions_retention_obligation": "30,60",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "filelocking.enabled": true,
        "filelocking.ttl": 3600,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379,
            "password": "***REMOVED SENSITIVE VALUE***",
            "timeout": 1.5
        },
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "25",
        "maintenance": false,
        "theme": "",
        "enable_previews": false,
        "activity_expire_days": 30,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "forwarded_for_headers": [
            "HTTP_X_FORWARDED_FOR"
        ],
        "default_phone_region": "FR",
        "mail_smtpauthtype": "LOGIN",
        "updater.server.url": "***REMOVED SENSITIVE VALUE***",
        "twofactor_enforced": "false",
        "twofactor_enforced_groups": [],
        "twofactor_enforced_excluded_groups": [],
        "app_install_overwrite": [
            "openotp_sign",
            "openotp_auth",
            "mindmap_app"
        ],
        "defaultapp": ""
    }
}

List of activated Apps

Enabled:
  - activity: 2.20.0
  - admin_audit: 1.18.0
  - auto_groups: 1.5.2
  - calendar: 4.6.6
  - circles: 28.0.0-dev
  - cloud_federation_api: 1.11.0
  - contacts: 5.5.3
  - contactsinteraction: 1.9.0
  - dav: 1.29.1
  - deck: 1.12.2
  - external: 5.3.1
  - federatedfilesharing: 1.18.0
  - federation: 1.18.0
  - files: 2.0.0
  - files_accesscontrol: 1.18.0
  - files_external: 1.20.0
  - files_pdfviewer: 2.9.0
  - files_reminders: 1.1.0
  - files_sharing: 1.20.0
  - files_trashbin: 1.18.0
  - files_versions: 1.21.0
  - forms: 4.1.1
  - group_default_quota: 0.1.8
  - groupfolders: 16.0.4
  - groupquota: 0.1.12
  - instance_quota: 0.1.1
  - integration_ews: 1.0.37
  - logreader: 2.13.0
  - lookup_server_connector: 1.16.0
  - notifications: 2.16.0
  - oauth2: 1.16.3
  - officeonline: 2.1.0
  - polls: 6.1.6
  - provisioning_api: 1.18.0
  - quicknotes: 0.8.22
  - quota_warning: 1.18.0
  - recommendations: 2.0.0
  - related_resources: 1.3.0
  - serverinfo: 1.18.0
  - settings: 1.10.1
  - sharebymail: 1.18.0
  - side_menu: 3.11.8
  - spreed: 18.0.4
  - support: 1.11.0
  - suspicious_login: 6.0.0
  - tables: 0.6.6
  - tasks: 0.15.0
  - text: 3.9.1
  - theming: 2.3.0
  - theming_customcss: 1.15.0
  - twofactor_backupcodes: 1.17.0
  - twofactor_totp: 10.0.0-beta.2
  - updatenotification: 1.18.0
  - user_migration: 5.0.0
  - user_saml: 6.1.1
  - user_status: 1.8.1
  - viewer: 2.2.0
  - workflow_script: 1.13.0
  - workflowengine: 2.10.0
Disabled:
  - bruteforcesettings: 2.8.0
  - comments: 1.18.0 (installed 1.8.0)
  - dashboard: 7.8.0 (installed 7.0.0)
  - encryption: 2.16.0
  - files_rightclick: 1.6.0 (installed 0.15.2)
  - files_videoplayer: 1.13.0
  - firstrunwizard: 2.17.0 (installed 2.7.0)
  - mail: 3.5.5 (installed 3.5.5)
  - nextcloud_announcements: 1.17.0 (installed 1.7.0)
  - notes: 4.9.2 (installed 4.9.2)
  - password_policy: 1.18.0 (installed 1.8.0)
  - photos: 2.4.0 (installed 1.0.0)
  - privacy: 1.12.0 (installed 1.2.0)
  - survey_client: 1.16.0 (installed 1.6.0)
  - systemtags: 1.18.0 (installed 1.8.0)
  - user_ldap: 1.19.0 (installed 1.19.0)
  - user_usage_report: 1.11.1 (installed 1.11.1)
  - weather_status: 1.8.0 (installed 1.0.0)

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

No files or tests are named. Reproduce the issue by accepting a circle invitation when an existing discussion includes the circle, then trace the invitation-acceptance flow and compare it with the direct-member-add behavior. Done means accepted members are added to the circle's existing discussions.