1. reordering from main chat list as described below:
tap on ... > manage pinned chats
in this case all the unpinned chats are hidden and you see only pinned chats with three-line button on the opposite of their titles to hold and drag up or down to reorder.
2. reordering from a section in app settings as described below:
go to Settings>Advanced>reorder pinned chats
Or
go to Settings>Chat settings>manage pinned chats(section)
There are two suggestions:
1. reordering from main chat list as described below: tap on ... > manage pinned chats in this case all the unpinned chats are hidden and you see only pinned chats with three-line button on the opposite of their titles to hold and drag up or down to reorder.
2. reordering from a section in app settings as described below: go to Settings>Advanced>reorder pinned chats Or go to Settings>Chat settings>manage pinned chats(section)
.