Thanks for the suggestion! So the only filter available related to date is “Due Date” which doesn’t completely solve my needs as I’d need to see all incomplete tasks regardless of due date (for example if something is overdue).
In digging around some more I was able to figure out what was happening. Those empty rows were displaying because they were “pinned”. No idea how this happened as I don’t recall pinning those groups of dates (screenshot below).
I would suggest that Coda not nest the only (AFAIK) control of that function so deep Options > Group > Group options and surface/display it on each pinned row (i.e a little pinned icon that can be clicked to remove it).