Default Help updating my radio HTC One m8

Hi! I have a question. now, I bought a HTC one m8 Tmobile from USA and then i was able to factory unlock using. It was sense version when it came here. I tried putting my Globe sim its working. But my reception is dropping even losing it all so i have to go to the settings and click the automatic in network operators. I converted it to stock non rooter GPE. Still my reception is dropping. Now, I saw some post about flashing radio for M8. Do I have to do this? I am in the Philippines. and if so what will I choose? AT&T, T mobile and WWE, DEV? my device is S off already.
its baseband 1.14.21
i have to change my CID to 1111111 something right? after i flash the radio can i go back to the google one? cause I read that it has to be like that for it to be updated ASAP. cause I am using GPe after all.
Thanks and God bless!

Okay, I tried updating it changed my CID and everything.got an error
failed remote 24 parsing android-info fail
I followed all the steps.
I think the reason why I keep on losing my reception is because of my firmware. any ideas? Thanks!