when reordering of single row - when made child of self it gets removed

[DevJobalia]

SAMPLE - https://snippet.dhtmlx.com/v0wukk8e

[gearcoded]

@DevJobalia,
Thank you for reporting the bug. I was able to reproduce the issue.
The child cannot be assigned to itself. But if you have only one task on the root level and you try to reorder it to the bottom, it obtains index 1. But when I call the gantt.moveTask(1,0,1) method, I cannot reproduce the issue.
It is unclear why it works that way and why it is reproduced only after you try to vertically reorder the task.
I added it as a bug to our internal bug tracker. The dev team will fix it in the future, but I cannot give you any ETA.

As a workaround, you can cancel calling the moveTask method when it is the root level and there are no other tasks:
https://snippet.dhtmlx.com/xlh26grd