As of the self damage update explosions have a big problem doing damage to Garry and Harry. On synovias they either dont register or do minimal damage - as if on max falloff, even if they are detonated directly on the target. On the last phase where all of the hitbox is supposed to be vunerable to damage, they do 0 damage. Note that those problems are not present on Terry and on Garry, sometimes synovias are more consistant, but only sometimes.
Those issues were still present in game versio