Generally the Auto complete control will refresh the section when you try to enter something or pressing the down arrow key in order to fetch the results in autocomplete field, which is an expected behavior. If you don't want your whole section to be reloaded then its suggested to place your autocomplete field in separate section, so that it will reload only that section instead of reloading the main section.
your answer is helpful, thank you for confirming this is the behaviour that is provided OOTB.
I think this is not something to be expected and has a performance impact which can result in a bad user experience (lagging response to keystrokes). I would expect that only the autocomplete field is refreshed on the keystroke, not the whole section it is placed.
@Gerg?T70 i agree with your point and that might be the reason our product specialists had asked to place the autocomplete control in different section as a local change and may be in future they might fix it.