There's nothing inherently wrong with "only" one bar, it's still a bar and it's a rough guide to service.
WiFi & mobile should have independent on-screen measurements, but the preference between them can vary depending on Apple/Android, and in some cases, user-selection.
Brief momentary audio drop-outs could be handovers, whilst dalek-type outgoing audio can be a symptom of poor radio conditions. Reporting the issue via the status tool referenced above, is as good a start as anything.
