Why is the explosion from 'Armour explosion' not detonating the gas clouds from 'Gas Arrow'?

Hello, Ranger here.
I noticed that the explosion from the 'Armour explosion' is not detonating the gas clouds from the 'Gas Arrow'. Is this a bug? The 'Armour explosion' has 'Fire' and 'Explosion' and should detonate the gas clouds or do I misunderstand something?