The conversations are actually still there and can be searched for. But for some unknown reason, whenever I open the project through the .code-workspace file, the chats won’t save to the corresponding project. Opening the folder directly works fine. This issue seems to have started from version 1.18.
My multi-root / cross-directory projects are now really frustrating. Every time I open one, I can’t see the previous conversations at all — I have to search for the conversation ID and then @ the ID to make the IDE remember what was said before.