Scold's Bridle damage taken is bugged

The new unique introduced this league, Scold's Bridle, Jade Tiara, is either bugged or has severe inconsistancies given the way PoE mechanics work.

Here's its unique mod:

Take #% of Mana Costs you pay for Skills as Physical Damage

The Physical damage you take is not considered a Hit. It's kinda frustrating, because the Ritualist ascension could play a very cool and niche build if its behavior was just like the other self hit mechanics, e.g. the Fireflower amulet, which also reads "Take X damage on ignite", which is considered a Hit.

Even in PoE 1 Scold's Bridle counted as a Hit on yourself. Please save my build GGG!

It does seem to be considered a hit.

You can verify that by enabling the Catalysis node on the tree, then using one of the unique charms like Ngamahu's Chosen or Valakro's Roar, which activate on Hit.

However, I've noticed that if the damage taken is below a certain amount, it won't register.

For instance, at 75% cap resists, with a helmet that takes 66% as damage, casting a skill with 95 mana always activates the charms, whereas with 26% damage, it doesn't. If I drop Fire Resist, it does.

I'm guessing if it's below 1 point of damage, it's not following the "round up to min 1 damage" rule.