I understand what may look like a url & what doesn't, as I've been using browsers for a good 30 yrs, including Safari, and it's never done this until this last year or so. If it's guessing, it's guessing wrong far too much of the time. ;-)
The fact that this also is happening with apps in the Dock, as well, where instead of opening when I click on them, a dropdown menu pops out, likely indicates an Apple issue beyond just Safari. However, it's odd that none of this happens when I use any other browser, only with Safari. I also seem to have far more issues with slowness (like now, typing requires me to type, then wait & wait for the letters to finally appear, before I can continue), buffering videos (despite a very fast WiFi connection), & very high memory & CPU usage, especially by WindowServer (usually at 6GB & 50-100%+ CPU), and other Apple System processes, whenever I use Safari, which of all the browsers, should be the one that runs the smoothest.
I'm going to try starting in Safe Mode, and see if these issues still appear. If I have no choice, I'll back up everything, then do a clean install or re-install... Maybe there's just some old stuff lying around that are the cause. I would think there might be some way that a new OS could handle cleaning out any old System &/or third party apps that are either obsolete or just in the way. Especially since all the "experts" on here constantly tell us we must not use any third party memory or process management apps, because "Apple's OS handles all that on its own"! Well, I think situations like mine belie that statement.