Yes, that can be a problem, but we don't have any control over the voltage on the USB port. It is what it is! Unfortunately I don't have a USB hub here to try although I might try other solutions. You may have noticed I've ordered one of your bias-t units, and also a low noise power supply, although I don't actually
need that. My old trusty home built 12/5 volt PSU with 7812 and 7805 regulators is just a bit large for where I want to put it.
With the higher supply voltage, the LA+ is working remarkably well and compares favourably with my Wellbrook loop. It's propped up against the fence at the moment and there's a chain-link fence immediately behind that.