whatsapp crashing in Iphone 15 promax

I bought new iPhone 15 Promax two weeks ago and transferred the WhatsApp from the old Iphone7plus to the new one. Since then whatsapp keeps crashing and messages that are not backed up went missing. I deleted the app restarted the phone and reinstalled the whatsapp from apple store. The reloaded the backed up messages. It crashes when I reload. I contacted whatsapp help centre. They said it out their scope of help they can provide. Went to apple store to ask if they can fix it. They reported no other person has reported this and that I should wait for software update from either apple or whatsapp. What should I be doing? What did I do wrong.