[Q] 4g calling issue after update

After the ota update to 4.4.2, my phone will only let me make 1 or 2 calls when on 4g and then I can no longer make/receive any calls (until I remove the sim card or sometimes just resetting the radio or clearing the dialer app data then maybe I'll get another call or 2 if I'm lucky).
I'm looking for any help or suggestions. I'm stock, S-On, etc. I've already tried a hard reset... I also reflashed the ota firmware, but had no change.

I found a temporary fix by changing to "gsm only" in the *#*#4636#*#* menu. However, that resets every reboot, and I don't want to be stuck on edge forever.

I would prefer to stay stock, S-On, but I'll take any suggestions...
Thanks in advance

In case it is helpful:
(bootloader) version: 0.5
(bootloader) version-bootloader: 1.56.0000
(bootloader) version-baseband: 4T.24.3218.09
(bootloader) version-cpld: None
(bootloader) version-microp: None
(bootloader) version-main: 4.18.502.7
(bootloader) version-misc: PVT SHIP S-ON
(bootloader) serialno: xxxx
(bootloader) imei: xxxx
(bootloader) meid: 00000000000000
(bootloader) product: m7_ul
(bootloader) platform: HBOOT-8064
(bootloader) modelid: PN0712000
(bootloader) cidnum: CWS__001
(bootloader) battery-status: good
(bootloader) battery-voltage: 4270mV
(bootloader) partition-layout: Generic
(bootloader) security: on
(bootloader) build-mode: SHIP
(bootloader) boot-mode: FASTBOOT
(bootloader) commitno-bootloader: dirty-c6bbb6d4
(bootloader) hbootpreupdate: 11
(bootloader) gencheckpt: 0

UPDATE: I have a few more details: I tried to call my phone, LTE turns off (which is normal), but it never rings then the 4g icon disappears for a minute like it crashed somehow.

enigma2446 said:

Well without achieving s off you are limited to running the ruu for your device. I suggest doing that first and if that don't help you might want to look Into s off for you can flash whatever you want.

"Coming to you live from my Straight Talk LTE One"

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I ran the ruu for the 4.18.502.7, but there was no change. Do you think there is any chance that it'll work if I flash something different, or is it a hardware issue?

As far as flashing is concerned: I've only done it before on my Galaxy S2 and it was fairly easy/straight-forward. Would you say it's the same for this phone? And is it easy to return to stock when I'm ready to trade-in?

finanandroid said:

After u run RUU you must do a Factory Reset* or phone reset from stock recovery or setting
This will reset your radios and every setting to factory state.

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Click to collapse

Still no luck. I think the ruu did a complete wipe too, but I tried anyways.

I have a few more details: I tried to call my phone, LTE turns off (which is normal), but it never rings then the 4g icon disappears for a minute like it crashed somehow.