I was trying to configure my TH16 FW 2.0.4 but it failed to connect to my Lynksys wrt 610n (1 blink, 2 sec pause, 1 blink). After a few hours it appeared to be related to WiFi's password - it was 0987654321. After adding some letters (aka kdr0987654321) the sonoff connected successfuly! Have ever had this problem?
I suppose sonoff interprets 0987654321 as HEX or OCT string?