Whatsapp msgs showing only in notification but not in chat log

I have installed whatsapp and when I receive a msg I can see it in the preview even if I receive more then one msg. When I open the chat to reply I do see the msgs until I close whatsapp. Once I close whatsapp and open it again, all the msgs are not visable in the chat history. Only older msgs are shown that are all prior to this issue I am having. Any suggestions? So far I have backed up whatsapp and deleted it and re installed it and restored the backup, rebooted the phone, removed battery saver but none seem to have solved the issue for me. Running ios 11.2.6 on I phone 6.