Default [Q] NO LTE?

So my lte/cdma mode doesnt seem to work at all, i know i have 4g but when i turn on my phone it says mobile network (under settings) connecting and then the mobile network type keeps flashing from lte to unknown, however if i i switch to cdma mode 3g works fine so does anyone know a fix to lte ? i already reflashed with odin and also restored and did all that (sm-g900r4) i also attempted to do a nanroid restore but that didnt fix it either :/