If you can still see your friend's timeline page, and it shows that you are friends, but they are not listed in your friends list, there are a few possible reasons for this:
Privacy Settings: It's possible that your friend has adjusted their privacy settings to restrict who can see them on their friends list. Some people choose to hide their friends list from the public or certain groups of people to maintain their privacy and control who can access that information.
Unfriending: Your friend may have unfriended you, which would remove them from your friends list. However, if they haven't blocked you, you can still see their public posts and timeline.
Restricted List: Facebook offers a feature called the "Restricted List," where users can add people they want to stay connected with but limit what those individuals can see on their profile. If your friend has added you to their Restricted List, you won't be able to see their posts on your News Feed, but you'll still be considered friends, and you can visit their timeline directly.
Technical Glitch: Occasionally, social media platforms can have technical issues that lead to inconsistencies or errors in displaying certain information, such as friends lists. This might be a temporary problem that will resolve itself over time.
Account Deactivation: If your friend has temporarily deactivated their account, they will not appear in your friends list until they reactivate it.
If you suspect that you have been unfriended and you want to confirm, try sending them a friend request. If you're already friends, the platform will let you know, and it will remain pending if they have unfriended you.
Keep in mind that social dynamics on social media can be complex, and people may make changes to their privacy settings or connections for various reasons. If you have concerns about your friendship, it's best to communicate directly with your friend to understand their intentions or ask if there have been any changes in your connection.