Initially I tried 4 x Primecare Devices (Balance 20X), and 1 normal (Surf Soho), in a Star with the FusionHub Solo as the Hub… that didn’t work.
Then I tried just the 4 x Primecare Devices…that didn’t work either.
Applying all these as point to point worked fine (currently have 5 x Point to Point’s with same devices working)
So I’ve updated the Firmware to the one you suggested, and interestingly now it doesn’t appear in the list of “Hub” devices when I try to create a hub…(that is with removing all the point to point links I’ve created previously)
…so cant really confirm it that helps…(I would suggest not!)
(I have a workaround using point to point…but its just a bit annoying!)