please help -No signal after reboot-

[mariusfilip]

Hello, I bought yesterday an unlocked Htc M8, european version(i live in Europe) and after every reboot, after i enter the pin, i have to toggle the airplane mode on/off to get signal, after that it's all ok, no signal drops or anything, i also have a moto g and with the same SIM i have no problems, i thought the phone is locked or something, but thanks to some tips on an article from Android Authority the solution was to toggle the airplane mode, what could be the problem? i have no warranty and thought to ask here maybe someone has had this issue, thanks