They don't cap upload, it all depends on traffic or congestion on the tower you are on. Only thing that is capped is hotspot at 5Mbps. I normally only get 1 to 2Mbps and sometimes up to 10Mbps but my download speeds are only around 30Mbps average. You can try resetting your network, don't factory reset, just network and see if that helps, if you do that don't forget to change you hotspot back to what it was or nothing will connect.
