Call dropping or caller does not hear me anymore

Hey there, since a few weeks i've huge issues with my mix2s... when driving home from work i call a lot with the same person for 30min and since a few weeks having a call is nearly inpossible…

the caller doesn't hear me anymore after a few minutes, then the call drops… in the beginning rebooting the phone did helped.. in the last few days even directly after rebooting the same issues starts to happen...

what i does see is that the signal bar sometimes drops, i guess the phone roams from...

Call dropping or caller does not hear me anymore