mobile

Hi everyone ,
i have a nexus 6 which i rooted, sideloaded 5.1 with disabled force encryption. Everything works fine besides some random lags which are no problem because they are just random and may happed and some other times dont happen. My main problem now is when i try to call someone or someone calls me and i pick up or even the time im talking, i lose network, it drops like dead with a wierd sound (a wierd bip) and i get the message "Network callular has stopped". After some seconds networks works again and i am able to call again. It never happed twice, maybe one time, it dont happens all the time, but it happens and when it does its very annoying. Is it maybe because the disabled force encryption? because this never happened before i sideloaded 5.1 and disabled force encryption. I sideloaded and disabled the force encryption the same day so i cant be sure if its the one or the other that caused it.

Thank you in advance guys