Telephone or video appointments can sometimes suffer from technical problems, (e.g. due to a busy network or sound delays). This can result in garbled talk, or blurry or frozen faces on the screen.
Having a good connection and equipment helps, but otherwise there may not be much you can do to change this. Basically, some telephone and video appointments may turn out to be less fluent than a face-to-face appointment.
You may need to repeat things or ask for clarification more often. If there has been a technical glitch, a good way to restart the appointment is to repeat the last thing you heard (or said).
It may help to make a comment about technical problems if they happen (e.g. "You are breaking up a bit").