@brentrobbo the SamKnows Real speedtest does seem to throw up some oddball results, as you say it doesn't make any sense for the speed to the hub to be less than that received by a device downstream from the hub. There's quite a few posting from other members here showing similar results plus, to be fair, some showing perfectly reasonable and consistent values so who knows? One answer might be that the consistency of the build quality of the hubs might be a little, shall we say, off - but of course that's just speculation! Personally, I really wouldn't bother too much about it.
Now in terms of the actual speed you are getting, the first thing I'd do is check that the Hub4 actually has been provisioned for 1 Gig and isn't still stuck on 350 Mb/s (it'll be in the network configuration settings).