Why should that via (Vdd, not GND as reported?) be connected to the GND pad of capacitor 4? Or am I reading that message incorrectly?
I double-checked the nets of all zones and the symbol definition of the regulator, and found no errors. Please note that the pin for which I’m creating the trace with vias is defined as passive – maybe this has something to do with it?
(Please ignore the other unconnected message, which is a bug.)
My best guess is that it has nothing to do with the pad.
Note that there is also a track segment with a length of 0.564mm which has an Y coordinate of 70.631mm, which is 6 mm lower (0,0 is in upper left corner) and probably just off screen, and KiCad is suggesting to connect it to Pad2 of C4 because that is the closest copper of that net.
It probably also helps if you turn on Pcbnew / View / Show Ratsnest. The ratsnest is a tool especially designed for visualizing unconnected items.
Thanks for your suggestion! The rats’ nest did point out the missing connection, and as you suspected, it wasn’t the via after all. (But then the “center on …” functionality of the DRC isn’t really doing what I thought it does …)