WhatsApp Chat History Missing on Infinix Hot 50

I am using an Infinix Hot 50 and I have experienced a serious problem with loss of message history. Since my wife started using the device with the WhatsApp number +62 878-8290-5***, the list of chats and messages has disappeared and I can no longer see the previous conversations. I did not make any backup of this data to an email account, and now I am trying to access it from another phone, a Realme Note 70, but the old chats are not visible there either. This situation is very important to me because I need to see the missing conversations that were on the Infinix Hot 50. I request that you examine this problem, inform me clearly why this loss of chat history happened, and guide me step by step on whether there is any way to recover or view the missing messages or chat list associated with that number. I expect a detailed technical explanation and support on this issue.