The viewport was the wrong signal: the nav rail and filter panel move the
row's width by ~430px between them, so at a 1280 window with both pinned
every column still qualified while the row had 762px for 766px of them —
the title squeezed back to nothing, the exact bug the breakpoints were
meant to fix. My own comment predicted it and I didn't follow it through.
VirtualFeed already measures the container for colCount, so it now passes
the item's real width down. Measured in the failing config: title -4 ->
359 with the date column standing down.
peter
be05c80d82