This is quite an interesting observation you've had. And I believe the going consensus is that the vitamin-c residue has effectively reduced your ionic silver into particle/or elemental silver. Which in turns results in a larger particle size in contrast to the ions which are extremely small and in most cases completely clear.
To which I'd add, you can replicate and confirm this by adding a pinch of vita-c powder to some ionic silver, at which point you'll likely see the solution turn yellow as it disperse.