It's not a bug. When the effects run out, fire, explosions and other effects may not display at the same time as the smoke effects are still in display, having used all the effects available, it may take a a few minutes to replenish completly.
I've got very annoying bug if using the stratospheric aerosol, after you pressing X in Andromada to activate the aerosol and till it empty, all effects include explosion, fire, etc. cannot dissappear.
