After deleting last message in cometchat and not get oldest message in api response after refreshing page

When i refresh the page i get an array of the last message with node text: “how are you”. if I delete my last message which is (how are you) in our chat window.The problem what I believe when I delete a message it’s not permanently deleted and remove node “text” from the last message After deleting the last message and after the refreshing page empty message on the user conversation list because in response from comet chat removes text node in the last message is undefined.