2 way audio unusable

I have 4 cameras;3 indoor cams, and 1 stick up cam (3rd gen)....the indoor cams are about 3 months old, the stick up cam I received today.All are connected to the same wifi, and of all, the stick up cam has the lowest wifi coverage.All 3 of the indoor cams are totally useless for trying to speak through, the audio is choppy and cuts out nearly all the words you speak. The stick up cam is totally perfect.It is not my wifi or internet as both are high speed, and in fact, as I said earlier, the stick up cam is the one with the "worst" coverage. I have deleted and factory reset the indoor cams to no improvement.It would seem to be a software issue to me, but its an important feature I need and currently its totally unusable.Any help would be appreciated.