I am using the weapon Mang, which will grant boosts to ATT equals to the amount of target Armor destroyed.
I thought I read somewhere that any boost modifier to ATT will automatically break entangle? Or was that feature never implemented?
Regardless, when I activated Mang while I was entangled, I did not gain any ATT boost, nor did it break me out of Entangle effect. Furthermore, when my Entangle status ended, the purported ATT boost from Mang was not available as well.
Is this a bug?
Yes this is, and they have had a lot of similar bugs to this in the past. The most recent one I can think of is if Kerberos was entangled and he consumed a target, he got the health buffs but not the attack buffs. I’m assuming they have code to get this bug out of everything come 1.0.7.
This is not a bug I think. It is supposed to work that way. It was changed on patch.
This will be addressed next update 
Didnt you guys changed the way it work this kind of thinks like 2 months ago? In that time it was fixed due to Gloom Leaf stoling atack from entangled troops and visual bugging their attack values @CrowdedWorlds