SMALL HELP please [ How to add WCDMA ONLY on huawei p8 dual ROOTED ] ??

Hello , i have Huawei P8 Gr-ul00 rooted and unlocked bootloader
I have only 4G/3G/2G MODE
Or
3G/2G(auto) mode
I want add
3G ONLY mode or WCDMA only mode
What i must change on system ? build.pro ? or band file ? Please help me what i must add to obtain this
I'm under 3G until it turn automaticly to EDGE , this make me crazy and i want destroy this phone :/

PLEASE HELP ME XDA members, you are my last chance

M8_UL always stuck on wcdma preferred..No singnal..Emergency calls only

Hey guyz..Me stuck in deep trouble .need help

i have M8_UL...i purchased its network unlock code...then when i insert sim..no signal..emergency calls only..but it detects sim...i officilally take ota update 4.4 to 5.0 but sme issue...what i do now..plz