Hey there,
Your chat data is not lost – the 26 transcripts on disk are intact. The problem is that the sidebar chat list is tied to an internal workspace identifier, and opening a different folder (or re-opening the same folder via a different method) can cause that identifier to shift. When it shifts, older chats become invisible in the sidebar even though the data is still on disk.
A few users have reported the same pattern – more details in this related thread: Chats disappearing after reopen
Workaround for now: Always open your project folder the same way (e.g., only via File > Open Recent or only via File > Open Folder to the exact same path). This keeps the workspace identifier consistent and should preserve the chat list between sessions.
The team is aware and tracking this.