cm-12.1-20150915-NIGHTLY-shamu problems with LTE!

I tried to flash this cm 12.1 with root and twrp and did it successfully, but I don't know what gapps to flash! Tested several 5.1.1 gapps but still doesn't get the LTE to connect to network.

Does anyone knows which gapps that will fix this problem?

/Daniel