The iMessage Pin functionality is a great feature added in iOS 14 and many iPhone users are liking this feature to ping conversation. This feature allows iMessage conversation to to be pinned at the top of conversation list. But many iPhone and iPad users are facing issues with pin messages keeps on disappearing. 

Pinned message getting disapper in iOS 14

This is a strange issue as the Pinned messages disappearing from iPhone but not from the iPad. For example pinned conversations stay on my iPad Pro but not on my iPhone 11 Pro.

In iOS 14 the pinned messages conversation disappear after some times and return to the list of messages. If you try to pin a conversation in iMessage it will show up on the top of the message app. But after sometimes or if you close the app, it will disappear from the pinned area. This is happening more frequently with group conversations. The and pinned conversation will go back to the list to you and If you find the group message again in the list it will give option to unpin the already unpinned message which is clearly a bug.

The pinned conversations getting removed automatically seems to be related to android users in the conversation as if you have to group conversation, and in one of the group conversation there is an android user, the group conversation with android user will get disappearing from the pinned section in the message app.

 issue with pinned groups mixed with Android users

But for some iPhone user it is not only related to an android user, individual or group, disappear if you close the messages app,User have to unpin it, then pin it again

How to fix iPhone text conversation getting disappeared in iOS 14: iPhone 11 Pro,XR, XS MAX, 8,7 Plus

Workaround 1 : Unpinned other pinned message

If you are seeing some of the pinned group conversation disappearing, then unpin one of the left pinned conversation. Now you will get option to re-pin both that message and the one that keeps disappearing to the top.

Workaround 2 : Edit the disappeared pin message

Since the disappeared pin message still shows option to unpin it when right Swift,Click Edit then Pins, you can select it and it will go back on top.  Not sure if it will stay or not, but this will do the trick 

Workaround 3 : Delete any other message thread (non important)

If you want to see the disappeared group conversations again at the top try deleting another message thread, any message thread at all, makes the missing pinned conversations reappear in the top part of the app, at least for me. 

Hope this fixes iMessage group messages getting unpinned iOS 14