Either they don't transmit position (unlikely that's the case for all) or your reception of those aircraft is too bad to get a position which needs 2 position messages within 10 seconds.
I now have a new antenna, tuned to 1090 MHz, in the clear. I am getting TONS of aircraft! Now, if someone knows how to make my computer stop dropping my Wifi I would love it.
WiFi via USB?
Only when you have the SDR plugged in?

Fixing WiFi problems is really hard.
Unless it's reception issues, then there isn't much you can do except relocate the base station or computer.
(well and get a better WiFi device can also work)
LAN is always better for a PC. In case of Wifi only, please check how many WiFi signals are being used in the area. An android app like Cellular-Z or inSSIDer can help. Choose a transmission band that is either empty or has the weakest signal in you area. Also make sure that the router firmware is up to date. You may also have to fiddle around with the Hardware Settings under Device Manager to see the Advanced and Power Management settings. This should be a good starting point.