When i tried backing up my old chat from google drive to my ne number on a new phone, it didnr detacted it. Does this mean i can only trasnfer chat if its the same number? If so how can i save my old chats on a new phone with a different number?
Chat history backup and restore feature can be used only to change the mobile device. Because the backup will be taken for the particular mobile number and can be restored in the same number.
There is an inbuilt option in the whatsapp messanger to change the phone number without losing the chat history. Please read the official documentaion to do the same.