0.50 Round Down (Instead Of Up)

I have my currency set as 0 decimal places, and I have the product price as USD 1,690.

When I apply a 5% Discount on the product, the calculated price is USD 1,605.50.

But the displayed price shows as USD 1,605 (instead of USD 1,606).

I've tried various pricing, and 1.60 gets rounded up to 2.00, and 1.40, gets rounded down to 1.00. Shouldn't 0.50 be rounding up instead of down?

Or am I not understanding the way the promotions are applied?

The promotion is a catalog promotion reducing the price by 5% of the product price.