I don't know if it has been reported already but when a pokemon that has harden as passive uses it while you're using one of it's atacks, the spell of the atack isn't gonna do any damage.
Rage has the same problem
We know it and we can't fix it for now, and Idk if we will be able to do it someday.so every buff passive should be checked, it might be general.
Well its normal.For example granbull hits 1k in 1x.When it hits bliss it will became 2k then with refelct granbull will deal 2x more damge to itself since its supereffective on itself too.Same thing goes with dragonite so its not a bugwhen granbull use sky up to other pokemon and this pokemon use reflect granbull lose 2x more hp for example atack to blissey she should lose 2x 2k when she use ref granbull lose 2x 4k hp.