I find the problem…That is system problem.
After I update openwrt back to old version, all my five bug boards work well. T-T, spend me a lot of time to catch that bug.
That is why my first board work. I think after I copy openwrt to my first board I just run “git pull & make”…
But on the log, both of them are OpenWrt R39957. So it is not version problem. HWAddr is load from FLASH factory area, maybe it is that problem. If I erase the flash, all data will set to 0xFFFFFFFF, same as the wrong HWAddr FF:FF:FF:FF:FF:FF. Just a guess, need time to check.