Canticle mods in Dante's 4 "Wordwarden" doesn't work

[SrmS2]

Hi!

So i'm not sure if this is intended or a bug, but let's go...
I'm testing some Dante builds and I made one where I have all canticle mods in noctua. It works as expected when using the tome directly, but when I use Wordwarden and shoot with another weapon, all mods (including on hit effects) are working, but not the canticle mods. 

According to warframe wiki, "Tome Mods with on-kill conditions do not require the Grimoire to make the killing blow. The Grimoire only has to damage the enemy once to mark it with Tome effects, then be equipped as the held weapon when the marked enemies are killed by other sources, such as Warframe abilities.". 
So I believe that the game considers that the tome isn't actually equiped, falling into the described exception. Is it the intended behavior? Or should the tome be considered as equiped and work with on-hit effects just like galvanized shot/diffusion?

Here is a quick video of the issue: https://drive.google.com/file/d/19vrQj-viWJNktacRH6oGWZnfLnrXLEbz/view?usp=sharing

Thank you in advance for your attention.

Edited March 28 by SrmS2