EDIT: Seems to have only occurred with one node that was apparently corrupted. The problem persisted when that node was duplicated, but not when a new sibling node was created.
It seems that date ranges are never showing in found dates, and that newly entered single dates are also not showing. At least some previously entered single dates are showing. This problem is quite new, but it might be a few days / versions old, as I think I observed it yesterday (Monday), maybe a little earlier. 4.3.2609011101 [beta, edge, win]