Old Chats/ History / Conversations Not Visible

Chat history not visible. 80% of chats before 4th May 2026 not visible. Previously while editing it was “send” option for editing messages and I could see my old chats with numbers underneath the edit message option Now it’s “overwrite” and I cannot see my old chats with numbers underneath the edit message. Tried all the options, logging out , clearing browser cache / history but no resolution Any one facing the same. Kindly advice/ suggest. This is impacting my work.