Default [Q] LTE after reboot

Hi all,

I bought my phone over eBay in the UK.
Since none of the cellular company in Ireland sell this handset it very hard to get any support.
at the moment I setup LTE manually but every time I reboot my phone i need to reset it.
Is there any way to avoid it and does the LTE take more battery power?

I'm on this version
Android version: 4.4.2
Baseband: M8974A-AAAANAZM-1.0.190084
Kernel: 3.4.0
Build: KOT49I.D80220b
Software: D80220b-HKG-XX

Thanks