Is there an reason why a rather vanilla SL-7.9 system might report “4
ports detected” on a new, Sabrent 7-port, powered USB 3.0 hub (HB-BUP7)?
Memory sticks are recognized only in 4 ports. (I just now checked one of
the other three for charging use, and it did appear, at least initially,
that the device attached was being charged. But the Sabrent is advertised
as having 7 data-transfer ports.)
I purchased the Sabrent because it was recommended on a linux website as
one of the most reliable for a linux system.