I recently had an issue where, upon returning to my computer, my recent chats had disappeared in the Teams desktop app, except for the one I was currently looking at. I loaded up the web app and it showed all of my chats just fine. I restarted Teams and cleared the AppData cache to no avail.
The solution is simple: log out and in again within the desktop app.
This will force the recent chat list to reload and you can save yourself a headache having to remember which groups you are a part of etc. If this doesn’t work, you can try the following:
- Delete the cache folder (AppData\Roaming\Microsoft\Teams\cache)
- Restart Teams (right click in taskbar -> Quit)
- Search for the names of people you have recently spoken with in the search bar/