Hi freshbird
1.my test is on Edison breakout board ,and my levelshift is TXS0102.
For i don't know much about ediosn arduino kit and BSS138. Maybe you can compare and find some differences.
2.Some advices
make sure your sensors can work well seperately.
make sure levelshift works well,oscilloscope can help a lot.
if pull up sensors are already in the levelshift there is no need to add extra pull up resistors for sensors in my case.
let me know if it helps~
Regards
ma jiayao