We analyzed the provided sample and we can able to reproduce the reported issue. This issue has been fixed already and included in our latest version. Kindly upgrade your version to v17.2.34.
In Gantt, to delete the record ,we need to call deleteRecord method from editModule.
Please find the code example below.
<button class="btn btn-danger" @click="remove">remove newly added task</button>
const ganttInstance = getGanttInstance();
Please find the sample from below link.
Jesus Arockia Sankaran S