I’ve found you added some code to fix below issues in 6.1.7
* Fix bug in the [Multiselect extension](https://docs.dhtmlx.com/gantt/desktop__multiselection.html) which caused selected tasks to lose highlight after chart repaint
But it causes another issue !! I can not get task item selected, cause isSelected method is replaced with multi-selected ext.
It is SO FRUSTRATED when you deliver code that is not full tested and have low quality, it causes us too much issues, this is how you deliver you product?
You should really check multi-selected is turned on or off !!!