The order of display of answers to my question (and completeness of that record) is different when I (1) click on the question or (2) reload the page via the browser "Reload current page" icon. (Note that I use an older Firefox browser; that may influence how the page is loaded.)
This is an intentional feature, if you have ordering by votes selected (which is the default).
In this mode, answers with the same vote total are placed in a random order every time the page is accessed, which is supposed to prevent other factors (such as submission time) from biasing the voting.
If you have selected one of the other ordering modes, "active" or "oldest", as far as I know the order in which answers are shown under those modes should be completely predictable and consistent.