Mt7601u Can not work on tp703 tp720 with op18 and lede17

tp703n tp720n lede 17.06 .2 .3 .4 .5 .6
tp720n op18.06.1
After installing mt7601u, you can see the wifi signal 100% can scan and can join the network.But as wwan can not get ip.
Raspberry pie b+ has problem mt7601u and can only work under lede 17.06.2.

Any solution Pleaaaase

I'm having same problem, some of you were able to get it working?