audio call: could not unpause audio only call

the scenario on iOS:

start audio-only call
pause call
unpause. The call stays in the paused state.

the scenario on the desktop client:

start audio-only call
start another audio-only call. The first call will be paused.
stop the second call, the first call stays in the paused state.

When a call is paused an exception is thrown: "Exception running job: Stream index is out-of-range"