Distorted sound on Ring doorbell

My doorbell sound is so distorted that the person at the door cannot understand what I am saying, so device is pretty much unusable. It used to work and still now the first few words I speak are clear, but after that is indecipherable! Have always been borderline with wi-fi signal even though doorbell, router and booster are literally within 3 metres of each other. Not sure if this is still the problem?