1) One primary reason for longer matching time is due to the liquidity issue of bonds. Bond transactions often depend on manual processing by traders, who need time to find suitable counter-parties, especially for less common or smaller volume bonds, where finding a counter-party can be more challenging.
2) On the other hand, when bond liquidity is poor and there is a significant difference in quoted prices, the reference prices may not reflect reality. Placing orders at reference buy/ sell prices might not find a matching buyer or seller.
Therefore, influenced by multiple factors such as bond liquidity, counter-party situations, and order prices. Thus, bond trade orders may take a longer time to execute.