The entry in safari is acting only as a search box it seems, and Go takes you to the first result that is finds - which is the first result on Google, likely a paid ad, or just coincidentally a higher ranking.
If you visit the realty.com site directly (Not suggesting this is a workaround, see thread), then type it in, Safari remembers it and gives it higher priority. This seems to be a quirk of a “first visit” UX - it still is meaningful to anyone who has competitors with similar names, and I’d call it a bug to not check the domain first, though assuming good intent, maybe it does, but something about that domain is not right for some heuristic (HSTS, something else?)