sometimes UltimateListCtrl items don't render automatically

Sometimes when I scroll (especially if I scroll fast) my UltimateListCtrl certain rows don’t show up until I click on them or scroll them out of view, then back into view (slowly).

I wrote a search function for items in this list, and am using SetItemState and Focus to highlight and scroll to my next search result… I’m finding sometimes when it jumps to a result far from the last result, those items don’t render (so it seems similar to the problem when I scroll fast).

Any ideas? I’m not sure where to start on this, maybe the OnPaint methods???