The skill of the swarm weapons do not refresh the acid duration when attempting to reapply it on an already drenched target.
The acid can only be reapplied once the effect has worn off from the enemy it is applied to.
Steps to Reproduce
Use the new skill for the swarm weapons.
Hit an enemy within the active duration, the acid will last for 10 strikes
Reuse the skill and hit an enemy again
Reuse the skill if deactivated, and hit the enemy again within the 10 strikes of acid
This 2nd hit will not reset its duration, and will run out on the 10th strike despite the attempt to reapply
A developer has marked this issue as fixed. This means that the issue has been addressed in the current development build and will likely be in the next update.