onAfterTaskDrag Fires Twice for Same Task When multiselect Is Enabled

Gantt
#1

Issue: onAfterTaskDrag fires twice for the same task when multiselect: true is enabled — even when dragging child task.(its happening only for child not for parent)

Expected: Should only fire once per actual drag.

Steps to Reproduce:

  1. Enable multiselect: true
  2. Drag a task
  3. Observe onAfterTaskDrag firing twice for the same task ID

Config:

gantt.plugins({
  multiselect: true,
  auto_scheduling: false
});

Version: DHTMLX Gantt 8.0.4

if i remove multiselect its firing only once
#2

Hello,
This issue should be fixed in the 8.0.7 version:
https://docs.dhtmlx.com/gantt/whatsnew.html#:~:text=Fix%20the%20duplicate%20event%20firing%20while%20interacting%20with%20a%20selected%20task%20when%20the%20Multiselect%20extension%20is%20enabled

#3

Issue: Grid lines and workload highlights are not rendering properly on high-resolution displays (e.g., 4K monitors, Retina Macs). Some visual elements (grid lines, workload background) are missing or misaligned.

Expected: Gantt grid lines and workload visualization should render correctly and consistently across all screen resolutions and devices.

#4

Hello,
It is possible that the grid lines won’t be visible on some screens if you change the brightness and contrast settings. For this use case, you need to modify the styles to use the higher contrast colors for the grid lines:

:root {
    --dhx-gantt-base-colors-border: silver;
    --dhx-gantt-base-colors-border-light: silver;
}

Here is the snippet:
https://snippet.dhtmlx.com/ep6vps5p

However, the lines shouldn’t be misaligned. If you can reproduce the issue in the official samples, please share a photo of how it looks on your screen:
https://docs.dhtmlx.com/gantt/samples/

If the lines are misaligned, most likely, it is related to the Gantt configuration. One of the common mistake is to set different height for the grid and timeline:
https://snippet.dhtmlx.com/q12zofnb

But this is not a Gantt issue. When you reach the bottom position, the grid cannot be scrolled, but you can still scroll the timeline:

The expected approach is to set the same height for the grid and timeline:

You can do that by adding a scrollbar to the timeline:
https://snippet.dhtmlx.com/72yx5nhg

Or you can add an empty cell and specify the height:
https://snippet.dhtmlx.com/awt0dk5e

If that doesn’t help you, it is hard to suggest what might be wrong as I don’t see your code. In that case, please add your configuration to the following snippet and make sure that the issue is reproduced there:

Then, click on the Save button and send me the link.
Or send me a ready demo with all the necessary JavaScript and CSS files so that I can reproduce the issue locally.