It's been explained many times that Luno Malaysia sells bitcoin in MYR and not USD. That is the bid/sell price you see in the Exchange where Bitcoin is sold and bought in MYR. Bitcoin prices are not converted from USD to MYR. So there are times that the price in the exchange does not match the exchange rate as Luno Malaysia is a much smaller market. Luno Malaysia is a local exchange only open for traders from Malaysia (with Malaysian IC) and it's not a global exchange.

That depends on the market sentiment on the exchange. During a short selling like now, people are just selling at bid prices and there is only a RM1 spread. When the market is bullish, buyers are picking up higher sell prices and increasing the spread. Here's a shot of the tightest spread you'd get a few minutes ago.