In vanilla Minecraft, attacking through grass, cobwebs, etc, is not possible as they have a hitbox and it would break them instead. So no, this isn't a bug.
TriggerBot is only activated when your crosshair is over an entity, so if any block, there be it even a transparent one is in the way, it won't activate.
If you are looking for hacks that can attack through any blocks, hacks like KillAura, MultiAura will do the trick if the setting "Check line of sight" is disabled.
Hope this helps!
