Dropouts if plugin source sink is not otherwise connected

[pallaswept]

I noticed during testing, that when I selected a source, it would link to the virtmic capture ports, and it would share as expected - However if I then un-linked the ports from my normal audio sinks, leaving it only linked to the virtmic sink (so that it could not be heard locally), then it would cause dropouts/long stuttering, at the receiving end

For example there would be sound for ~0.5 seconds, then silence for ~2.5 seconds, and that would repeat quite rhythmically. I cannot help but notice the ratio is related to the fact that there are 6 audio outputs from the sink and and only 2 being captured by the virtmic device, but I do not have any 2 channel sources to test this, as all of my clients are upmixed (although I could alter my config for testing, but perhaps you will be able to see if you can reproduce this, if you do not use upmixed sources)

Allowing/forcing a larger quantum request from firefox seemed to work around this issue, but is undesirable as it increases latency.

I would not consider this urgent as this is probably not a real problem in most real scenarios where you would also be listening to whatever source you are sharing, but I can think of scenarios where disconnecting that source might be desirable (so you can play something to someone else but don't have to hear it)