Layout collapsable & resizable error

I made a layout with collapsable and resizable applied like the source below.
Layout collapsed by clicking on the header.
Then, if you expand the collapsed layout again after resizing with the mouse, the layout disappears.
I am wondering how to solve this error.

		docLayout = new dhx.Layout("layout_wrap", {
			type: "line"
			, rows: [
				{
					resizable : true
					, height:300
					, cols: [
						{
							header : "REPORT"
							, collapsable : true
							, resizable : true
							, width:400
							, rows: [
								{id:"a"}
							]
						}
						, {
							header : "TASK"
							, collapsable : true
							, resizable : true
							, rows: [
								{id:"b"}
							]
						}
					]
				}
				, {
					header : "SCHEDULE"
					, collapsable : true
					, resizable : true
					, rows:[
						{id:"c", height:"35px"}
						, {id:"d"}
					]
				}
			]
		});

Thank you for your report. THe problem is confirmed and will be fixed in the next dhx.Suite update.

Your reported problem was fixed in the latest dhx./Suite update (7.3).
Now, this scenario should work correctly. You can check it in the following snippet:
https://snippet.dhtmlx.com/pdvdg56e
Please, try to download the latest available dhx.Suite build to get that fix.