"The connectivity icon in the system tray often goes from green to red..."
The WLAN icon in the NA is neither green nor red, so I am not sure what you are refering to.
Are you running this adapter with its own 3rd-party software or in a driver-only state? (I suspect the former, based on your comment about the WLAN icon).
The other - more important - consideration is router placement. You can sit right next to a badly placed router and fail to establish any connection at all.