Sorry about coming to this thread late. From the symptoms, it sounds like it’s indeed a compatibility issue. The chip we use is ESP8266, which is very popular in the open-source hardware community (and in fact many commercial products too these days). I did search for “esp8266 Wireless-B WAP11” and didn’t find any existing report of incompatibility. It’s also possible that the issue was due to the firmware back then was compiled with an earlier version of the WiFi library, and since then we’ve updated the firmware and used the latest WiFi library. We have a new firmware (2.1.8) that will be released by this weekend, which may address the compatibility issue with some routers. At any rate, thanks for finding out the issue and reporting it.