Have had this happen too. Usually I signout and back and it works, but one time i had it worse where the changed reservation would toggle back and forth from the old data to the correct flight data - prompting me that confirmation XYZABC had changed over and over. Would cycle ever 1-2 minutes.

Sign out and back did not work at that time.

I sent an email to the app feedback address and one of their people responded and told me to delete the app and reinstall it.

That actually worked, but was annoying.