Can be reproduced with following macro:

TFile::Open("https://root.cern/js/files/hsimple.root");
hpxpy->GetXaxis()->SetRange(0, 5);
hpxpy->GetYaxis()->SetRange(14, 26);
hpxpy->Draw("candle2");

For the first bins full interval drawn wrongly.
Rectangle around 50% of counts shown ok, but lines which should show 99.9% of existing values are absolutely wrong - they are drawn inside of 50% rectangle.

This happens while center of bin is used when searching for that interval.
If there is only non-empty bin in the histogram,
interval is 0. If one uses lower and upper bin, picture will look:

PR will follow soon