The Firewall enchantment (35% Lucky Hit to spawn 2 firewalls when inflicting Burn damage) does not get triggered by the Hydra skill (with the +Burn enhancement node enabled).
A post on the Blizzard forum suggests that the bug has been in effect since March of 2023: [SORCERESS][BUG] firewall enchantment not working with all sources of burning - #12 by helios-2322
Please patch the game so that the enhanced Hydra skill appropriately procs the Firewall enchantment. Thank you!