Hi @daianere and welcome to the community!
A few things worth trying. First, in any chat window try typing “Restore my recently deleted chat” as quick can sometimes recover conversations deleted within the last 7 days. Beyond that, try logging out and back in, and make sure your app is on the latest version. Another user had a similar issue and was able to recover their data by locating the local profile folder on their machine. The steps they followed are documented here: I lost all my chats, context, etc after software update.
If none of that helps, I’d recommend opening an AWS Support case (Case management - AWS Support). They can investigate whether anything is recoverable on the backend.
Hope this helps!