After some digging I found that the onDragStart method within block-reorder.js creates a cloned element, however if the block is an embed, then the process never completes, so st-block--dragging class is never removed from the block and it looks like its crashed.
The following method seems to work perfectly without generating the text preview:
onDragStart: function onDragStart(ev) {
var block = this.block;
ev.dataTransfer.setData("text/plain", this.blockId());
this.mediator.trigger("block-controls:hide");
EventBus.trigger("block:reorder:dragstart");
},
After some digging I found that the
onDragStart
method withinblock-reorder.js
creates a cloned element, however if the block is an embed, then the process never completes, sost-block--dragging
class is never removed from the block and it looks like its crashed.The following method seems to work perfectly without generating the text preview: