Gas arrow explosion deals less damage occasionally

When shooting an ignited monster with gas arrow it deals less damage than it would if the monster was not ignited, and the gas was manually exploded.

The difference can especially be seen when wearing Radiant Grief - the explosions while wearing this helm are very different than the ones when a monster is hit directly

Holy damn, i thought i was going crazy! Yes, this is happening for some reason, the damage feels very off