Arcane Surge + Arcane Cloak + CWDT

Arcane Surge doesn't trigger from Arcane cloak when linked with Cast when damage taken. I know triggered spells don't have a mana cost, but Arcane cloak always spends mana to give the shield. I saw no reason in the current wording of the skill gems for why this setup wouldn't work.
I also made sure Arcane cloak spends the correct amount of mana to trigger the surge.

Steps to reproduce:
- Link arcane surge support with Arcane cloak and Cast when damage taken
- Take damage
- See the Arcane cloak buff
- Notice Arcane surge doesn't proc

My apologies if this is intentional.

Any update ? Is this interaction (or lack thereof) intentional ?