I just setup a 3T with LOS 15.1 and it is working perfectly apart from any Pro versions of apps.
There seems to be a problem checking licences with Google on all of them and they just hang on the checking page.
I have tried clearing cache, unins...
TWRP mounted as read/write or read only?
I swiped to allow modifications at the start.
any one in topic tested this problom on android 5.1 ?
does problem solved or not?
The problem remains in 5.1.1.