Anyone? It seemed simple in theory...I bought both a splitter and a hub but neither did the trick. When I plugged in either to either of my two USB ports on my laptop and then plugged in things to the additional ports, still only a max of two worked such that I gained nothing. ?
I've used a lot of USB hubs on a lot of desktops and laptops, both PC and Mac. I usually don't have a problem, though I have found that my desktop doesn't see some devices that I plug into my powered hub (I think it can't read USB thumb drives, but I don't remember for certain).
OK, I cheated and asked Google Gemini for suggestions. As a computer technician, I'm embarrassed, but I also can fact-check what Gemini tells me:
This problem is not a standard USB limitation and usually points to one of two critical issues: a controller limit on the host computer or a faulty internal design of the USB hub.
1. Host USB Controller Resource Limit
The most likely technical explanation for a limit matching the number of physical ports on the computer is that you are running out of USB Controller resources (Endpoints).
The Problem: If all the USB ports on your computer are wired to a single, small internal controller, plugging in a multi-port hub may not provide much benefit. Once you plug in devices that collectively exceed the endpoint limit of that single controller, all subsequent devices, even if plugged into the hub, will fail to be recognized. This limit is often hit quickly with devices like webcams, audio interfaces, and capture cards, which are high-bandwidth and use many endpoints.
[I think this might be more likely to happen if you have a budget laptop. - Opcode]
2. Faulty or Non-Compliant Hub Design
The USB hub you are using may be malfunctioning or poorly designed in a way that limits its expansion capability.
Hub Not Actually a Hub: In rare cases, the device you are using might not be a true USB hub but simply a passive splitter or an adapter with limited functionality that is designed to only extend the original port to a few accessible ports without adding real expansion capability.