Flex in Flex Mr-Auto funktioniert nicht

// add width to 100% inside flex wrapper dive
<div class="d-flex p-2">
                                <div class="profile-avatar mr-2">
                                    <img class="avatar-img" src="/images/Avatar" alt="avatar">
                                </div>

                                <div class="w-100">
                                    <div class="d-flex mb-1">
                                        <h6 class="text-truncate mb-0 mr-auto">Name</h6>
                                        <p class="small text-muted text-nowrap last-updated" datetime="Timestamp"></p>
                                    </div>
                                    <div class="text-wrap text-break p-1 message">message.Content</div>
                                </div>
                            </div>
code fighter