Potential bug in UAITask_MoveTo [unconfirmed]

Acharacter possessed by an AAIController.
An APawn possessed by an APlayerController.
An APawn wich we will call target.

The APlayerController generates locations with GetHitResultUnderCursorForObjects and sets the APawn to it. The AAIController is running a UAITask_MoveTo task with bUseContinuousGoalTracking set to true and set to follow the target. It uses a navmesh and pathfinding.
Behaviour is like league of legends or any game like that.

This works just fine until the Acharacter is stuck → doesnt move anymore. This always happens when a path is finished. There is no way to trigger or predict it. But eventually it will happen.
I tracked it down with the visual logger that the UPathFollowingComponent of the AAIController is broadcasting OnPathFinished but that signal never reaches the UAITask_MoveTo.
maybe someone could try to replicate it?

I use 5.1 but had same problem in 4.7