Viper Strike of the Mamba + Ambush

Hello devs,
I'm pretty sure there is bug with the new transfigured gem "Viper Strike of the Mamba" (VSOTM) but I can't prove it.

Here's the settup:
Equip two daggers, have a lot of crit chance (using the new tincture +25% crit chance, might be the source of the issue ..?), use ambush, then hit a full life enemy.
I do have a lot of damage on my poison, but only if you crit. Every time I just go on a pack an use VSOTM, the pack instantly disappear. Strangely enough, MOSTLY EVERY TIME I use ambush the result is a weak poison.
Path of building helped me understand the skill. It uses both weapons in one strike if dual wielding (as in the description); so both weapon contribute in it's own way to compute the damage. But what happens for crit ? Does both weapons need to crit ? Only one (if so, wich one)?
My crit chance is not that good if the enemy is not on full life, since the character is build around the new tincture. I'm using ambush to add +25% against enemies that survives, but it doesn't seem to work.

My humble assumption:
The attack is exerted with ambush, but it only count for one weapon. The second one doesn't benefit from the increased crit chance, so most of the time, it doesn't crit. VSOTM doesn't count the resulting poison as "from a crit" => poison is weak.
I don't believe there is a lot of skills using both weapon in a single hit (not cast), so this might be a difficult bug to spot.

Hoping I'm not telling complete non sense,
Thanks for your time !

(by the way, good work for Affliction league)

Ambush does say

Teleports you to a nearby enemy, applying a buff to you for a short duration and blinding the enemy for a secondary duration. Performing a melee attack with a One-Handed Weapon removes the buff to exert that attack.

I assume that it does only apply to One of the weapons which seems like it would be better to be for Both weapons when used as a dual hit skill like VSOTM or also Dual strike in the same situation.

That is really a shame to hear that the dual hit is not working for crit like this with Ambush as I was hoping to build it as crit and take advantage of the Ambush mechanic for the first time.

It makes me want to rethink the rebuke of the vaal as the BIS with tinctures as well if putting on a shield now to take advantage of that crit scaling.

Was considering Paradoxica and replica abyssus

Exerted attacks should be using both weapons for the rare attack like this that would use both.