It works - for me - with any combination of Macs; old or new, desktop or laptop, on any given network configuration; in any location - about 3 or 4 out of ten times I give it a shot.
It’s honestly baffling to me how Apple has for more than a decade shipped a major feature that works easily less than half the time in my experience and my co-workers. Coworkers and I mostly completely avoid it at this point; and if we do actually give it a try, it feels more like praying to a God for rain than actually trying to use a piece of software.
I really have to wonder what has made it just so, brutally; unusably broken, for more than a decade.
I just guess nobody at Apple cares?