AmChart CustomSymbol - TimeProvider - Navigation Link

Hi

i've created a custom symbol based on the amchart-trend symbol from the Osisoft GitHub repository.
I just made some changes to allow it to display stacked area charts.

Then, i added some code to allow users to change display start time and end time by zooming in the chart.

I did that using two listenner from the amchart library and the 'TimeProvider' parameter. See the code below :

That works great.
Well it seems... the problem is :

When a zoom is made in the graph, display start and end time are actually updated, but then if i use a link (wich is on the same display) to go to another one, i get the following error :

The navigation link is setted to "set start and end time"

I don't understand why i get this message...

Any ideas how to fix that ?

Thanks