Unable to use Dual Strike of Ambidexterity while dual wielding Varunastra and a sword

If player equips Varunastra + sword OR Varunastra + Varunastra - they will be unable to use Dual Strike of Ambidexterity. Dual Strike of Ambidexterity requires the player to weild two different melee weapon types. Since Varunastra counts as all one-handed melee weapon types - players should be able to use the gem. Especially considering that passives like "60% increased damage while holding two different Weapon types" have full effect on Varunastra paired with a sword.

Players are able to use Dual Strike of Ambidexterity with Varunastra + Claw/Axe/Hammer/Dagger, so it is definitely Varunastra + sword issue. My guess is that Varunastra is considered a unique sword, that's why it doesn't work, but in that case passives shouldn't work either.