Those who having same problems like me had: -> random reboots ,network / signal drop , no simcard detected esue !
I tried all kinds of roms ,and all versions of it like ,global stable ,china stable, dev rom's but none of them helped!
I requested the unlock permission ,after two day i recieved it ,actually i unlocked my phone the first try without any esue (while my phone was softbricked with 6.10.13 dev rom ,no clue how ,used MiFlas and it flashed succesfully without any esue ,lol ?! ) , after that the second day i recieved the sms , actually i got my permission before receiving sms not after ! lol
Steps:
1 unlocked my bootloader
2 installed TWRP (do a backup, you never know)
3 wipe dalvik /cache /system
4 installed the 8.0.6.0 EU rom (october) (i installed it over 7.5.4.0 global stable)
5 installed SuperSU (2 reboot loops -this is normal)
6 done, 3 days now,no random reboot's no signal drops and network loss / no servce problem's anymore for me !!!