When activate multiselect plugin (multiselect: true) and set multiselect_one_level: true then there is issue with single selection in different levels.
Example structure:
1. Parent Task (parent1)
a. Child Task (child1)
Then if I click on child1 then it gets selected. After that I click on parent1 to select it, but there is just child1 deselected. I have to click one more time to select parent1. (this issue is in both directions parent > child, child > parent)
I have this listener there:
https://docs.dhtmlx.com/gantt/api__gantt_onbeforetaskmultiselect_event.html
This event is called for each task and there is passed state: true if the task is going to be selected, false - if unselected
for child1 it is false which is correct
for parent1 it is true which is correct too - but task is not selected
here is example: https://snippet.dhtmlx.com/toee6hh7