bundys , Mar 15, 2018 : Hi. My partner owns an OP2 that I gave him. The case is that always, I with her (OP5> OP2) I get a horrible echo in calls, it only happens to me and generally, after about 5-10s after establishing the call, with other people does not occur to me, so that my OP5 is not. The fact is that it happens the same with other people, because I hear it when someone calls, it is quite annoying. It happened in the last OOS available for OP2 and in a Custom ROM that I put in the last weeks with Android 8.1. With this casuistry, completely discarding problems of hardware or software of other mobile phones, the problem is in the OP2, the fact is that I do not know if ... editing the sound files like what happened in my old OnePlus One , we can solve something. What do you recommend? Remove a SIM? try to change it from slot? .... touch something in the configuration or an app that manages to do something with this? It has a call recording program, ACR, maybe it has something to do, I'll check the configuration.