I had the same problem (in fact two of mine wouldn’t connect to an AP on channel 11, and worked but with very weak signal on channel 1). The same solution worked for me; afterwards I can connect to channel 11 just fine, and the reported signal strength reported from the AP on channel 1 has improved by between 15 and 20 dB. I’m guessing that the antenna is either defective or maybe soldered on backwards or something. Mine were also the ones with the black/white antenna.